TEST BANK for Introduction to Probability and Statistics by William Mendenhall, Robert Beaver & Barb by StudyGuide

Chapter 01 - Describing Data with Graphs 1. A variable is a characteristic that changes or varies over time, and/or for different individuals or objects under

consideration. An experimental unit is the individual or object on which a variable is measured. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 2. Bar and pie charts are graphical techniques for qualitative data. The former focus the attention on the

frequency of the occurrences of the categories, and the later emphasize the percentage of occurrences of each category. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 3. In a sample of 1000 students in a university, 125 of them or 12.5% are biology majors. The 12.5% is an

example of statistical inference. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 4. Individual observations within each class may be found in a frequency distribution. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 5. Twenty-five percent of a sample of 200 professional tennis players indicated that their parents did not play

Chapter 01 - Describing Data with Graphs

tennis. This is an example of descriptive statistics as opposed to inferential statistics. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 6. A local cable system using a sample of 1000 subscribers estimates that fifty percent of its subscribers watch

premium channel at least five times per week. This is an example of inferential statistics as opposed to descriptive statistics. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 7. Statistical inference is the process of making an estimate, prediction, or decision about a population based on

sample data. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 8. In the term "frequency distribution," frequency refers to the number of data values or measurements falling

within each class. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 9. A branch of the statistics discipline that is used to develop and utilize techniques for effectively presenting

Chapter 01 - Describing Data with Graphs

numerical information is called inferential statistics. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 10. A branch of the statistics discipline that is used to develop and utilize techniques for properly making

inferences about population characteristics from information contained in a sample drawn from this population is called inferential statistics. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 11. Persons or objects that have characteristics of interest to statisticians are called variables. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 12. A qualitative variable about which observations can be made in only two categories is a bivariate data set. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 13. A variable that is normally described in words rather than numerically is a qualitative variable. a. True

Chapter 01 - Describing Data with Graphs b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 14. A discrete quantitative variable is one that can assume values only at specific points on an interval of

values, with inevitable gaps between them. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 15. A continuous quantitative variable is one that can assume values at all points on an interval of values, with

no gaps between possible values. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 16. Persons or objects on which an experiment is performed are called experimental units. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 17. Groupings of data, created to enhance an understanding of them, usually by making the groups collectively

exhaustive and mutually exclusive are called classes or categories. a. True b. False

Chapter 01 - Describing Data with Graphs ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 18. A tabular summary of categorical data set showing the number of observations that fall into each of several

collectively exhaustive and mutually exclusive classes is called a bar chart. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 19. A relative frequency distribution is a tabular summary of a data set showing the proportions of all

observations that fall into each of several collectively exhaustive and mutually exclusive classes. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 20. Descriptive statistics deals with methods of: a. organizing data b. summarizing data c. presenting data in a convenient and informative way d. all of the above e. only organizing and summarizing data ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 3/15/2019 4:47 AM 21. The relative frequency of a class is computed by:

Chapter 01 - Describing Data with Graphs a. dividing the frequency of the class by the number of classes b. dividing the frequency of the class by the class width c. dividing the frequency of the class by the total number of observations in the data set d. subtracting the lower limit of the class from the upper limit and multiplying the difference by the

number of classes e. adding the lower limit of the class to the upper limit and multiplying the sum by the number of classes ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 22. Which of the following is not the goal of descriptive statistics? a. summarizing data b. displaying aspects of the collected data c. reporting numerical findings d. estimating characteristics of the population based on a sample e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 23. You asked ten of your classmates about their weight. Based on this information, you stated that the average

weight of all students in your university or college is 158 pounds. This is an example of: a. descriptive statistics b. statistical inference c. sample d. population e. sample and population ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 3/15/2019 4:50 AM 24. The best type of chart for comparing two sets of qualitative data is:

Chapter 01 - Describing Data with Graphs a. a line chart b. a pie chart c. a histogram d. a bar chart e. all of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 25. The sum of the frequencies for all classes will always equal: a. the number of classes b. the class width c. the total number of observations in the data set d. one e. the average ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 26. The two graphical techniques we usually use to present qualitative data are: a. bar chart and histogram b. histogram and pie chart c. bar chart and pie chart d. line chart and stem and leaf plot e. bar chart and line chart ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 27. Which of the following statements is true? a. Univariate data result when a single variable is measured on a single experimental unit. b. Bivariate data result when less than two variables are measured on a single experimental unit. c. Multivariate data result when more than two variables are measured.

Chapter 01 - Describing Data with Graphs d. Both univariate data result when a single variable is measured on a single experimental unit and

multivariate data result when more than two variables are measured are true. e. Both bivariate data result when less than two variables are measured on a single experimental unit and multivariate data result when more than two variables are measured are true. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 28. Characteristics possessed by experimental units are called: a. data sets b. descriptive statistics c. internal data d. variables ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 29. A politician who is running for the office of governor of a state with 7 million registered voters commissions

a survey. In the survey, 55% of the 10,000 registered voters interviewed say they plan to vote for her. The population of interest is the: a. 7 million registered voters in the state b. 10,000 registered voters interviewed c. 55 %, or 5,500 voters interviewed who plan to vote for her d. 45%, or 4,500 voters interviewed who plan not to vote for her e. 55% of the 7 million registered voters in the state ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 30. Which of the following statements is correct? a. Univariate data result when a single variable is measured on a single experimental unit. b. Bivariate data result when two variables are measured on a single experimental unit. c. Multivariate data result when more than two variables are measured. d. All of these statements are true.

Chapter 01 - Describing Data with Graphs e. None of these statements is true. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 31. The set of all possible observations about a specified characteristic of interest is: a. a frame b. a multinomial data set c. an observational study d. a population e. all of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 32. A single observation about s specified characteristic of interest is: a. a datum b. an elementary unit c. a univariate data set d. a population e. none of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 3/15/2019 5:01 AM 33. A listing of data in order of ascending or descending magnitude is called: a. a frequency distribution b. a relative frequency distribution c. a relative frequency histogram d. none of these e. all of these ANSWER: POINTS:

d 1

Chapter 01 - Describing Data with Graphs QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 34. Which of the following statements is false? a. When constructing a frequency distribution for categorical data, it will always be necessary to

develop class boundaries. b. It is often a good idea to convert frequency distributions to relative frequency distributions when you compare two distributions with different amount of data. c. A pie is the familiar circular graph that shows how the measurements are distributed among the categories of a qualitative variable. d. None of these. e. All of these. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 35. A market share of 78.5 percent would be represented in a pie chart by a slice with a central angle of: a. 78.5 degrees b. 39.3 degrees c. 282.6 degrees d. 141.3 degrees e. 157 degrees ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 36. Which of the following statements is true? a. In constructing a pie chart for a categorical variable, one sector of the pie is assigned to each category

of the variable. b. A bar chart for a categorical variable shows the same distribution of measurements in categories as the pie chart, but with the height of each bar measuring how often a particular category was observed. c. The categories for a qualitative variable should be chosen so that a measurement will belong to one and only one category, and each measurement has a category to which it can be assigned. d. In constructing a pie chart for a categorical variable, one sector of the pie is assigned to each category of the variable and a bar chart for a categorical variable shows the same distribution of measurements in categories as the pie chart, but with the height of each bar measuring how often a particular

Chapter 01 - Describing Data with Graphs

category was observed. e. All of these. ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 37. A hospital administration would like to know the average length that a patient stays in the hospital. It would

be almost impossible to look through all of the past records and average the lengths of stay. Instead, a sample of 1000 patients over the last year was randomly chosen and their lengths of stay were averaged. Describe the population and sample in this problem.

Population:

Sample: ANSWER:

The lengths of stay of all the patients that the hospital has ever had; The lengths of stay of the 1000 patients sampled POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 38. A highway department would like to repair a certain highway during the slowest part of a day to help

minimize traffic congestion. Because it would be impossible to monitor the traffic flow on every day, they monitor how many vehicles pass on this highway during one particular day. Based on these results the department decides when to repair the highway. Describe the population and sample in this problem. Population: Sample: ANSWER:

All the traffic flow on all days on that highway; The vehicles that passed on that highway on the particular day they recorded POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 3/15/2019 5:04 AM

Chapter 01 - Describing Data with Graphs 39. The freshness and overall quality of milk depend upon the type of packaging used. The manager of a dairy

company is considering changing the packaging from cartons to plastic. The quality control team of this dairy company packaged milk in 100 containers of each type of material. After a specific amount of time, the team tested the milk for freshness and overall quality. Identify the population and sample in this problem.

Population:

Sample: ANSWER:

All of the milk packaged at this particular dairy company; The 100 selected containers of each type of packaging

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 40. Identify each of the following variables as either quantitative or qualitative.

a. The brands of ice cream that you purchase.

b. The daily high temperature for the last four weeks.

c. The amount of sugar consumed by Americans in one year.

d. The species of fish in the zoo.

e. The lengths of time children wait for the school bus.

f. Your favorite professional football team.

Chapter 01 - Describing Data with Graphs

ANSWER:

qualitative; quantitative; quantitative; qualitative; quantitative; qualitative

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 41. Identify each of the following variables as either quantitative or qualitative.

a. Rating of the effectiveness of a new cold remedy (Not effective, effective).

b. Amount of time spent assembling a five-shelf bookcase.

c. Number of children in a beginning swimming class.

d. University where a student is enrolled.

e. Color preference for a nursery.

f. Rating the U.S. foreign policy in the Middle East (fair, biased).

ANSWER:

qualitative; quantitative; quantitative; qualitative; qualitative; qualitative

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:06 AM

Chapter 01 - Describing Data with Graphs DATE MODIFIED:

2/4/2019 3:06 AM

42. Identify each of the following quantitative variables as discrete or continuous.

a. Average monthly temperature for a particular city.

b. Number of employees of a statistical consulting firm that own laptop computers.

c. Flight time between two cities.

d. Number of puppies enrolled in an obedience class.

e. Number of persons on a flight from Chicago to Los Angeles.

f. Amount of gas purchased at a gas station.

ANSWER:

continuous; discrete; continuous; discrete; discrete; continuous

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 43. Classify the following variables as qualitative or quantitative. If quantitative, further classify as discrete or

continuous. a. The colors of cars at an auction.

Chapter 01 - Describing Data with Graphs

b. The amount of money spent building a new school.

c. The genders of U.S. Senators.

d. The styles of houses (one-story, two-story, split level, etc.).

e. The letter grades of students in a statistics exam (A, B, C, D, F).

f. The number of credit cards owned by customers.

ANSWER:

qualitative; quantitative,discrete; qualitative; qualitative; qualitative; quantitative, discrete

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 2/4/2019 3:06 AM 44. Classify the following variables as qualitative or quantitative. If quantitative, further classify as discrete or

continuous. a. The breeds of cats living in Washington.

b. The weights of male students.

c. The blood group of patients.

Chapter 01 - Describing Data with Graphs

d. The treatment received by subjects in the experiment (A, B, or C).

e. The education level of school principals.

f. The number of mobile phones owned per household.

ANSWER:

qualitative; quantitative, continuous; qualitative; qualitative; qualitative; quantitative, discrete

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 3/15/2019 5:46 AM 45. Describe the difference between a population and a sample, and provide two examples for each. ANSWER: A population is the collection of all measurements of interest to the investigator in

a particular study. A sample is a subset of measurements selected from the population of interest; Population: all website visitors; Sample: website visitors who participated in the survey; Population: men aged 40-55 years; Sample: men who participated in the study POINTS: 1 QUESTION TYPE: Essay HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 3/15/2019 5:59 AM 46. Describe the difference between descriptive statistics and inferential statistics, and give an example for

each. ANSWER:

Descriptive statistics consists of procedures used to summarize and describe the important characteristics of a set of measurements. Inferential statistics consists of procedures used to make inferences about population characteristics from information contained in a sample drawn from this population; Descriptive statistics: The researcher determines average salaries for various occupations in Ohio; Inferential statistics: The researcher wants to test a new flu vaccine. She divides participants of the experiment into two groups. The first group receives new vaccine. The second group receives placebo. The researcher measures the number of people who get flu in both groups. Then she analyzes the measurements and concludes whether the new vaccine is effective or not for all people.

Chapter 01 - Describing Data with Graphs POINTS: 1 QUESTION TYPE: Essay HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:06 AM DATE MODIFIED: 3/15/2019 6:54 AM 47. A bar chart in which the bars are ordered from smallest to largest is called a Pareto chart. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 48. A relative frequency distribution describes the proportion of data values that fall within each class, and may

be presented in a histogram form. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 49. Compared to the relative frequency histogram, the stem and leaf plot provides more details, since it can

describe the individual data values as well as show how many are in each group, or stem. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 3/15/2019 6:17 AM 50. The difference between a histogram and a bar chart is that the histogram represents quantitative data while

the bar chart represents qualitative data. a. True b. False ANSWER:

True

Chapter 01 - Describing Data with Graphs POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 51. The largest value in a set of data is 100, and the lowest value is 20. If the resulting frequency distribution is

to have five classes of equal width, the class width will be 16. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 52. A relative frequency distribution describes the proportion of data values that fall within each class. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 3/19/2019 3:42 AM 53. The class interval in a frequency distribution is the number of data values falling within each class. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 54. A stem and leaf plot describes two-digit integers between 30 and 80. For one of the classes displayed, the

row appears as 5|234. The numerical values being described are 25, 35, and 45. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False

Chapter 01 - Describing Data with Graphs HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 3/15/2019 7:45 AM 55. The total area of the six bars in a relative frequency histogram for which the width of each bar is five units is

5. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 56. When a distribution has a greater proportion of the measurements to the right of the peak value, we say that

it is skewed to the left. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 3/15/2019 7:51 AM 57. Time series data are often graphically depicted on a line chart, which is a plot of the variable of interest over

time. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 58. When a distribution has a greater proportion of the measurements to the left of the peak value, we say that it

is skewed to the right. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False

Chapter 01 - Describing Data with Graphs DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 3/15/2019 7:53 AM 59. A histogram is said to be symmetric if, when we draw a vertical line down the center of the histogram, the

two sides are identical in shape and size. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 60. A skewed histogram is one with a long tail extending either to the right or to the left. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 3/15/2019 7:54 AM 61. A dotplot is a graphical portrayal of an absolute or relative frequency distribution of continuous quantitative

data in such a way that lower and upper limits of data classes are identified by tick marks on a horizontal axis, while the corresponding absolute or relative class frequencies are represented by the areas of contiguous rectangles that stand on top of each of these class intervals. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 62. A pie chart is a portrayal of divisions of some aggregate by a segmented circle in such a way that the sector

areas are proportional to the sizes of the divisions in question. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False

Chapter 01 - Describing Data with Graphs DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 3/15/2019 7:56 AM 63. For the same data, a relative frequency histogram will have the same overall shape as a frequency histogram. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 3/15/2019 7:58 AM 64. When constructing a relative frequency distribution, if the data are discrete, it will always be necessary to

develop class boundaries. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 65. Relative frequency distributions are specifically constructed for analyzing discrete data. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 66. If you wish to compare two data sets of different sizes, it is usually a good idea to convert frequency

distributions to relative frequency distributions. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM

Chapter 01 - Describing Data with Graphs 67. A relative frequency histogram can be constructed for qualitative as well as quantitative data. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 68. A relative frequency histogram can be constructed by letting the horizontal axis or the vertical axis represent

the variable of interest. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 69. The four classes: less than 5, 5 to < 10, 10 to < 20, greater than 20, would be acceptable for developing a

frequency distribution. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 3/19/2019 3:36 AM 70. Stem and leaf plots are often used to analyze qualitative data in most real life applications. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 71. One of the differences between a bar chart and a histogram is that a histogram typically displays data in a

percentage form. a. True

Chapter 01 - Describing Data with Graphs b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 72. Bar charts can typically be formed with the bars vertical or horizontal without affecting the interpretation. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 73. In a line chart, the horizontal axis represents time (such as months, years) and the vertical axis represents the

value of the variable of interest. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 74. The data values plotted on a line graph are connected with a straight line between each pair of successive

points. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 75. The common graphical presentation of qualitative data is the: a. stem and leaf plot b. histogram c. pie chart

Chapter 01 - Describing Data with Graphs d. dotplot e. time series plot ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 3/15/2019 8:10 AM 76. Which of the following statements is not true? a. One form of descriptive statistics uses graphical techniques. b. One form of descriptive statistics uses numerical techniques. c. A distribution is skewed to the left if it contains a few unusually large measurements. d. Statistical inference is used to draw conclusions or inferences about characteristics of populations

based on sample data. e. A distribution is not symmetric if it is skewed to the left. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 3/15/2019 8:15 AM 77. The total area of the six bars in a relative frequency histogram for which the width of each bar is ten units is: a. 6 b. 10 c. 16 d. 60 e. 1 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 78. The total area of the bars in a relative frequency histogram: a. depends on the sample size b. depends on the number of bars c. depends on the width of each bar d. depends on the population size e. depends on the frequency

Chapter 01 - Describing Data with Graphs ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 79. In general, incomes of employees in large firms tend to be: a. skewed to the right b. skewed to the left c. symmetric d. unknown ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 80. The sum of relative frequencies found in a relative frequency distribution for quantitative data necessarily

equals: a. 0 b. 1 c. 100 d. n, the number of observations in the data set e. the number of collectively exhaustive and mutually exclusive classes in a frequency distribution ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 3/18/2019 1:41 PM 81. Which of the following best describes a relative class frequency? a. It is the number of observations that fall into a given class in a frequency distribution. b. It is the proportion of all observations that fall into a given class in a frequency distribution. c. It is the difference between the numerical lower and upper limit of a class of quantitative data. d. It is the number of observations that fall into the smallest class in a frequency distribution. e. None of these. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice

Chapter 01 - Describing Data with Graphs HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 3/18/2019 1:42 PM 82. Given 180 observations, a data class with an absolute class frequency of 36 must have a relative class

frequency of: a. .10 b. .20 c. .36 d. .18 e. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 83. A graphical portrayal of a relative frequency distribution of continuous quantitative data in such a way that

lower and upper limits of data classes are identified by tick marks on a horizontal axis, while the corresponding relative class frequencies are represented by the areas of vertical rectangles connected to each other and stand on top of each of these class intervals, is called: a. a bar chart b. a frequency polygon c. a pictogram d. a time series plot e. none of these ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 84. A histogram is a graphical device that is commonly used to analyze: a. time series data b. quantitative data c. qualitative data d. all of the above e. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice

Chapter 01 - Describing Data with Graphs HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 3/18/2019 1:44 PM 85. A common rule of thumb in constructing a relative frequency histogram is to use: a. less than 5 classes b. more than 10 classes c. between 5 and 12 classes d. any number of classes e. at least 10 classes ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 86. Which of the following is not recommended when constructing a relative frequency histogram? a. equal width classes b. mutually exclusive classes c. open-ended classes d. all of the above e. none of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 3/18/2019 1:45 PM 87. A histogram is usually used to display which of the following characteristics for a quantitative variable? a. the shape of the distribution b. the spread or variability in the data c. the approximate center of the data d. the spread or variability in the data and the approximate center of the data e. all of these ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM

Chapter 01 - Describing Data with Graphs 88. A bar chart is used to display a: a. time series data b. continuous variable c. qualitative variable d. quantitative variable e. discrete variable ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 89. Which of the following statements is false? a. A bar chart and histogram can be used interchangeably. b. The bars on a bar chart have the same width. c. It is possible to construct a dotplot for quantitative data. d. There are gaps between the bars in a bar chart. e. All of these. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 3/18/2019 1:48 PM 90. One of the differences between a histogram and bar chart is: a. that the bar chart does have gaps between the bars and the histogram does not b. that the histogram is used to display the distribution of quantitative data and the bar chart is used to

display qualitative data c. that the bars of the bar chart can be reordered and the bars of the histogram cannot d. all of the above e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 3/19/2019 1:47 AM 91. The stem and leaf plot is used to display the distribution of:

Chapter 01 - Describing Data with Graphs a. qualitative data b. quantitative data c. two quantitative variables on the same chart d. all of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 3/19/2019 1:49 AM 92. If the manager of a grocery store wishes to display the sales trend, the most effective type of graph will be: a. a bar chart b. a pie chart c. a histogram d. a line chart e. all of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 93. The owner of an Italian restaurant would like to see a graphical display of the number of customers that the

restaurant serves. The following data are the average number of customers served each day for the last 12 months. Month Average

Jan 180

Feb 177

Mar 160

Apr 154

Construct a line graph. Explain what the graph tells us.

May 163

Jun 180

Jul 185

Aug 165

Sep 150

Oct 179

Nov 240

Dec 256

Chapter 01 - Describing Data with Graphs ANSWER:

The restaurant serves the most customers in November and December, which may be because of the holiday season. It also has a peak in mid-summer and dips in the spring and fall. POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 3/28/2019 8:32 AM 94. A math teacher would like to present the midterm results to her class in a way that shows the overall spread

of the data. The 25 test scores for the midterm are listed below. a. Construct a dotplot. 45 78 62 98 50 61 91 89 57 64 77 69 82 73 70 73 79 80 68 72 62 65 78 50 95 b. Explain what the plot tells us. ANSWER:

The points are fairly evenly distributed between 45 and 98, with most scores between 60 and 80. POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED:

2/4/2019 3:07 AM

Chapter 01 - Describing Data with Graphs DATE MODIFIED:

3/28/2019 8:44 AM

95. The librarian of a small community library has compiled the number of people who visited the library and

the respective number of checked-out books, and created the line chart shown below:

Interpret the chart, where the solid line is the number of visitors and the dashed line is the number of books checked-out.

ANSWER:

The two lines track each other. This means as the number of visitors increase (or decrease) the number of books checked out increases (or decreases).

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 96. A limnologist is studying a Minnesota lake in October. He records the temperatures in °C for surface water

taken every other day at noon. The data are shown below. 8.5 8.1 7.9 9.0 7.7 7.3 7.1 6.8 9.2 6.8 6.3 7.0 6.5 5.7 5.9 4.9 4.2 6.9 a. Construct a stem and leaf plot to display the distribution of the data. Stem 4 5 6 7

Leaf

Chapter 01 - Describing Data with Graphs

8 9 b. Would you describe the distribution of the data as symmetric, skewed to the right or skewed to the left?

c. Explain.

ANSWER:

2, 9; 7, 9; 3, 5, 8, 8, 9; 0, 1, 3, 7, 9; 1, 5; 0, 2; Symmetric; The distribution seems to be symmetric since the left and right sides of the distribution, when divided at the middle value, form mirror images.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM 97. The following data represents the number of pages of notes per lecture taken by a student in a beginning

statistics course. 1 5 2 6 2 3 3 4 4 4 5 5 5 5 5 5 6 6 6 6 6 6 6 6 5 6 4 5 6 a. Construct a dotplot to describe the data. b. Would you describe the distribution of the data as symmetric, skewed to the right or skewed to the left?

c. Explain. ANSWER:

Skewed left; The distribution of the data is skewed to the left since the distribution contains few small measurements at the left side and many large measurements at the right side. POINTS:

Chapter 01 - Describing Data with Graphs QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: DATE MODIFIED:

2/4/2019 3:07 AM 3/28/2019 8:51 AM

98. A neighborhood ice cream vendor would like to see if there is a relationship between day of the week and

the number of children buying ice cream from her. The following data represent the number of children buying ice cream on each of the seven days of a particular week: Day Mo Frequency 4

a. Construct a line chart to describe the data. b. Is there any apparent trend in the data? ANSWER:

The number of children buying ice cream decreases from Monday to midweek, Wednesday, then increases to a maximum on Sunday. POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 3/29/2019 4:13 AM 99. A high school volleyball coach has summarized the wins, losses, and ties of her team for the past 4 years in

the following stacked bar chart. Interpret the chart.

Chapter 01 - Describing Data with Graphs

ANSWER:

The team's best year was 2001 and their worst was 1998.

POINTS: 1 QUESTION TYPE: Essay HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:07 AM DATE MODIFIED: 2/4/2019 3:07 AM

Chapter 02 - Describing Data with Numerical Measures 1. Numerical descriptive measures computed from population measurements are called parameters. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 2. Numerical descriptive measures computed from sample measurements are called statistics. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 3. Two classes, one with 15 students and the other with 25 students, took the same test and averaged 85 points

and 75 points, respectively. If the two classes were combined, the overall average score of the 40 students would be 80 points. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 4. The population mean, , is used to estimate the sample mean, . a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 5. If the sample mean is much larger than the sample median, the data set is said to be skewed to the right. a. True

highest frequency is called the modal class, and the midpoint of that class is taken to be the mode. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 7. The mode is generally used to describe large data sets. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 8. The mode of a data set or a distribution of measurements, if it exists, is unique. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 9. Mound-shaped data tend to cluster around a middle value. a. True b. False ANSWER: True POINTS: 1

Chapter 02 - Describing Data with Numerical Measures QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 10. Jessica has been keeping track of what she spends to eat out. The last week's expenditures for meals eaten

out were $15.69, $15.95, $16.19, $20.91, $17.49, $24.53, and $17.66. The mean amount Jessica spends on meals is $18.35. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 11. A data sample has a mean of 87, and a median of 117. The distribution of the data is skewed to the right. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 3/18/2019 2:22 AM 12. A student scores 89, 75, 94, and 88 on four exams during the semester and 97 on the final exam. If the final

is weighted double and the four others weighted equally, the student's final average would be 90. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 13. In a mound-shaped distribution, there is no difference in the values of the mean, and median. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False

Chapter 02 - Describing Data with Numerical Measures HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 14. Measures of center are values around which observations tend to cluster and that describe the location of

what in some sense might be called the "center" of a data set. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 15. The median is a measure of center that divides an ordered array of data into two halves; if the data are

arranged in ascending order from smallest to largest, all the observations below the median are smaller than or equal to it, while all the observations above the median are equal to it or larger. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 16. The mode is the sum of a data set's minimum and maximum values, divided by 2. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 3/18/2019 2:23 AM 17. If the variability of a set of data is very small, then the sample variance may be negative. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False

Chapter 02 - Describing Data with Numerical Measures DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 18. When all the numbers in the data set are the same, the standard deviation must be zero. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 3/18/2019 2:24 AM 19. In all cases, the sum of the deviations of the measurements from their mean is 0. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 20. The sample variance is approximately the average of the squared deviations of the measurements from their

mean. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 21. The sample variance calculated with a divisor of n gives a better estimate of the population variance,

than does the sample variance, , with a divisor of n – 1. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 3/18/2019 2:40 AM

Chapter 02 - Describing Data with Numerical Measures 22. The larger the values of the sample variance

and sample standard deviation s, the greater the variability in

the data. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 23. In order to measure the variability in the same units as the original observations, we compute the sample

variance. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 24. Measures of variability describe typical values in the data. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 25. The mean is one of the most frequently used measures of variability. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 26. The range is considered the weakest measure of variability. a. True

Chapter 02 - Describing Data with Numerical Measures b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 27. For large data sets, the range is not an adequate measure of variability. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 3/18/2019 2:31 AM 28. The value of the standard deviation will always exceed that of the variance. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 29. The standard deviation is expressed in terms of the original units of measurement but the variance is not. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 30. The value of the standard deviation may be either positive or negative, while the value of the variance will

always be positive or zero. a. True b. False ANSWER: POINTS:

False 1

Chapter 02 - Describing Data with Numerical Measures QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 31. The standard deviation is the positive square root of the variance. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 32. A sample of 20 observations has a standard deviation of 4. The sum of the squared deviations from the

sample mean is 76. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 33. The value of the mean times the number of observations equals the sum of all of the observations. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 34. In a histogram, the proportion of the total area which must be to the left of the median is less than 0.50 if the

distribution is skewed to the left. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False

Chapter 02 - Describing Data with Numerical Measures DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 35. In a histogram, the proportion of the total area which must be to the left of the median is more than 0.50 if

the distribution is skewed to the right. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 36. If two data sets have the same range, the variances in both sets will be the same. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 37. The sum of the squared deviations from the mean is always zero. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 3/18/2019 2:35 AM 38. Measures of variability are numbers that indicate the spread or scatter of observations; they show the extent

to which individual values in a data set differ from one another and, hence, differ from their central location. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 3/18/2019 2:35 AM

Chapter 02 - Describing Data with Numerical Measures 39. A parameter and statistic can be used interchangeably. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 40. The median is one of the most commonly used measures of variability. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 41. For distributions of data that are skewed to the left or right, the median would likely be the best measure of

center. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 3/18/2019 2:46 AM 42. You are given the data values 5, 10, 15, 20, and 25. If these data were considered to be a population, and you

calculated the mean, you would get the same answer as if these data were considered to be a sample from another larger population. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 43. The value (n + 1) / 2 indicates the value of the median in an ordered data set, where n is the number of data

values.

Chapter 02 - Describing Data with Numerical Measures a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 44. For any distribution, if the mean is equal to the standard deviation, you can infer that the distribution is

symmetric. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 45. A distribution is said to be skewed to the right if the population mean is larger than the sample mean. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 46. One advantage of using the median as a measure of center is that its value is not affected by extreme values. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 47. A data set in which the mean and median are equal is said to be bimodal data. a. True b. False ANSWER: False

Chapter 02 - Describing Data with Numerical Measures POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 48. If the mean value of a distribution is 85 and the median is 67, the distribution must be skewed to the right. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 49. One of the advantages of the standard deviation over the variance as a measure of variability is that the

standard deviation is measured in the original units. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 50. For any distribution, the standard deviation is a measure of variability of the data around the median. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 51. Suppose the standard deviation for a given sample is known to be 12. If each data value in the sample is

multiplied by 3, the standard deviation will be 36. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False

Chapter 02 - Describing Data with Numerical Measures HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 52. Which measure of center is meaningful when the data are qualitative? a. the mean b. the median c. the mode d. all of the above e. none of the above ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 3/18/2019 2:57 AM 53. Which of the following statements is true? a. When the distribution is skewed to the left, mean > median. b. When the distribution is skewed to the right, mean < median. c. When the distribution is symmetric and unimodal, mean = median. d. When the distribution is symmetric and unimodal, mean = variance. e. None of these is true. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 54. Which of the following statements is true for a symmetric distribution? a. The mean is greater than the median. b. The mean is less than the median. c. The mean and median are equal. d. All of the above. e. None of the above. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 3/18/2019 3:01 AM

Chapter 02 - Describing Data with Numerical Measures 55. In a histogram, the proportion of the total area which must be to the right of the mean is: a. less than 0.50 if the distribution is skewed to the left b. exactly 0.50 c. more than 0.50 if the distribution is skewed to the right d. exactly 0.50 if the distribution is symmetric and unimodal e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 56. Which of the following statements is true for the following data values: 17, 15, 16, 14, 17, 18, and 22? a. The mean, median and mode are all equal. b. Only the mean and median are equal. c. Only the mean and mode are equal. d. Only the median and mode are equal. e. The mean, median and mode are all different. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 57. Since the population is always larger than the sample, the population mean: a. is always larger than the sample mean b. is always smaller than the sample mean c. is always larger than or equal to the sample mean d. can be smaller than, or larger than, or equal to the sample mean e. is always smaller than or equal to the sample mean ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 58. The average score for a class of 35 students was 70. The 20 male students in the class averaged 73. The 15

female students in the class averaged: a. 73

Chapter 02 - Describing Data with Numerical Measures b. 70 c. 66 d. 60 e. 35 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 59. Which of the following statements about the mean is not always correct? a. The sum of the deviations from the mean is zero. b. Half of the observations are on either side of the mean. c. The mean is a measure of the middle (center) of a distribution. d. The value of the mean times the number of observations equals the sum of all of the observations. e. None of the above. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 3/18/2019 3:31 AM 60. In a histogram, the proportion of the total area which must be to the left of the median is: a. exactly 0.50 b. less than 0.50 if the distribution is skewed to the left c. more than 0.50 if the distribution is skewed to the right d. between 0.25 and 0.75 if the distribution is symmetric e. all of the above ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 3/18/2019 3:32 AM 61. Data about qualitative variables can be summarized by: a. measures of center b. measures of variability c. proportions

Chapter 02 - Describing Data with Numerical Measures d. measures of relative standing e. all of the above ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 3/18/2019 3:46 AM 62. Which of the following best describes measures of center? a. They are numbers around which observations tend to cluster and that describe the location of what in

some sense might be called the center of a data set. b. They are numbers that indicate the spread or scatter of observations and show the extent to which individual values in a data set differ from one another and, hence, differ from their central location. c. They are numbers that indicate the degree of asymmetry in a frequency distribution. d. All of the above. e. None of the above. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 3/18/2019 3:46 AM 63. Consider the data set: 5, 6, 7, 11, and 15. Its mean equals: a. 7.0 b. 8.8 c. 8.1 d. 7.3 e. 9 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 64. Which of the following statements about the median is correct? a. It is a measure of center that divides an ordered array of data into two halves. b. If data are arranged in ascending order from smallest to largest, all the observations below the median

are smaller than or equal to it, while all the observations above the median are equal to it or larger. c. If the total number of observations is odd, the median is the middle observation in an ordered array; if

Chapter 02 - Describing Data with Numerical Measures

the total number of observations is even, the median is the average of the two middle values. d. All of the above. e. None of the above. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 3/18/2019 3:47 AM 65. A random sample from an unknown population had a sample standard deviation of zero. Which one of the

following is a reasonable conclusion? a. The sample range must be zero. b. An error was made in computing the sample standard deviation. It must always be greater than zero. c. The population standard deviation must be zero. d. The population standard deviation must be zero when the mean is zero. e. None of the above. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 3/18/2019 3:48 AM 66. The following data represent a sample of 10 scores on a 20-point statistics quiz: 16, 16, 16, 16, 16, 18, 18,

20, 20, and 20. After the mean, median, range and variance were calculated for the scores, it was discovered that one of the scores of 20 should have been an 18. Which of the following will change when the calculations are redone using the correct scores? a. mean and range b. median and range c. mean and variance d. range and variance e. mean, range, median and variance ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 67. Which of the following represents a disadvantage of using the sample range to measure spread or

dispersion?

Chapter 02 - Describing Data with Numerical Measures a. It produces spreads that are too large. b. The sample range is not measured in the same units as the data. c. The largest or smallest observation (or both) may be an outlier. d. All of the above. e. None of the above. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 3/18/2019 3:49 AM 68. The following ten scores were obtained on a 20-point quiz: 4, 5, 8, 9, 11, 13, 15, 18, 18, and 20. The teacher

computed the usual descriptive measures of center (central tendency) and variability (dispersion) for these data and then discovered an error was made. One of the 18's should have been a 16. Which one of the following measures, calculated on the corrected data, would change from the original computation? a. mean and standard deviation b. mean and median c. range and median d. mean and range. e. mean, standard deviation, range and median ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 3/18/2019 4:12 AM 69. Which of the following statements is true for the following data values: 17, 15, 16, 14, 17, 18, and 22? a. The mean, median and mode are all equal. b. Only the mean and median are equal. c. Only the mean and mode are equal. d. Only the median and mode are equal. e. The median and mode are not equal. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 70. Which of the following statements is true?

Chapter 02 - Describing Data with Numerical Measures a. The sum of the deviations from the mean is always zero. b. The sum of the squared deviations from the mean is always zero. c. The standard deviation is always smaller than the variance. d. The distance between the first and third quartiles is twice the distance between the first and second

quartiles. e. None of these is true. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:13 AM DATE MODIFIED: 2/4/2019 3:13 AM 71. Which of the following is not a measure of variability? a. the variance b. the standard deviation c. the mean d. the range e. all are measures of variability ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 2/4/2019 3:14 AM 72. If two data sets have the same range: a. the distances from the smallest to largest observations in both sets will be the same b. the smallest and largest observations are the same in both sets c. both sets will have the same variance d. both sets will have the same interquartile range e. both sets will have the same mean ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 2/4/2019 3:14 AM 73. A sample of 25 observations has a standard deviation of 4. The sum of the squared deviations from the

sample mean is: a. 21 b. 25

Chapter 02 - Describing Data with Numerical Measures c. 100 d. 384 e. 400 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 2/4/2019 3:14 AM 74. Numbers that indicate the spread or scatter of observations in a data set are: a. measures of center b. measures of location c. measures of variability d. measures of shape e. all of the above ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 3/18/2019 4:11 AM 75. The variance is: a. a mean of absolute deviations b. a mean of positive and negative deviations c. a mean of squared deviations d. a mean of positive deviations e. no mean at all ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 3/18/2019 4:13 AM 76. If a store manager selected a sample of customers and computed the mean income for this sample, he has

computed: a. a parameter b. a statistic c. a qualitative value

Chapter 02 - Describing Data with Numerical Measures d. all of the above e. none of the above ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 3/18/2019 4:14 AM 77. Which of the following statements is true? a. The population mean will always be larger than the mean of a sample selected from that population. b. The population mean will always be larger than the population median. c. The population mean and the mean of a sample selected from that population will usually be different

values. d. The population mean will always be equal to the population median. e. All of the above. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 3/18/2019 4:14 AM 78. A sample of students who have taken a calculus test has a mean score of 78.2, a mode of 67, and a median

score of 67. Based on this information, the distribution of test scores is: a. symmetric b. skewed to the right c. skewed to the left d. bimodal e. none of the above ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 3/18/2019 4:18 AM 79. Which of the following is the most frequently used measure of variation? a. the mean b. the range c. the mode

Chapter 02 - Describing Data with Numerical Measures d. the standard deviation e. the median ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 3/18/2019 4:20 AM 80. Which of the following measures is not affected by extreme values in the data? a. the mean b. the median c. the variance d. the range e. the standard deviation ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 2/4/2019 3:14 AM 81. Suppose that the distribution of actual weight of students in your university or college is thought to be

symmetric. If the average weight is 168 pounds, what would the median weight be? a. larger than 168 pounds b. smaller than 168 pounds c. 168 pounds d. There is not enough information to answer this question. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 2/4/2019 3:14 AM 82. The time required for ten children to learn a particular motor skill was recorded as 9, 15, 23, 20, 16, 15, 24,

18, 10, and 20 minutes. a. Find the mean time to learn a particular motor skill. Round your answer to the nearest whole number.

b. Find the median time to learn a particular motor skill. Round your answer to the nearest whole number.

Chapter 02 - Describing Data with Numerical Measures

c. Based on the values of the mean and median in parts (a) and (b) above, are the measurements symmetric, skewed to the right or skewed to the left?

Explain.

ANSWER:

17; 17; Symmetric; Since the mean and median values are the same, we conclude that the measurements are symmetric.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 3/18/2019 4:31 AM 83. You are given the following measurements: 0.10, 0.25, 0.20, 0.15, and 0.16.

a. Multiply each of the values by 100, and calculate the sample mean for the new data. Round your answer to two decimal places.

b. Without actually calculating the sample mean, what was the mean of the original data? Round your answer to three decimal places.

ANSWER:

17.20; .172

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 3/18/2019 4:29 AM 84. A sample of eight doctors was asked how many flu shots they had given to patients this fall. The numbers of

flu shots were 6, 3, 5, 24, 2, 6, 0, and 8. a. Find the sample mean. Round your answer to two decimal places.

b. Find the sample median. Round your answer to two decimal places.

Chapter 02 - Describing Data with Numerical Measures

c. Based on the values of the mean and median in parts (a) and (b) above, are the measurements symmetric, skewed to the right or skewed to the left?

Explain.

ANSWER:

6.75; 5.50; Skewed right; Since the mean is larger than the median, we conclude that the measurements are skewed to the right.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 3/18/2019 4:33 AM 85. In assembling a home appliance, workers generally finish the process within 30 minutes to one hour.

Occasionally, due to system failures, the assembly process takes a long time, possibly as long as 4 to 5 hours. What is the most appropriate measure of central tendency to use in this case if you want the measure to be representative of most of the observed times?

Why is it the most appropriate measure?

ANSWER:

Median; Median is the most appropriate measure because it is not influenced by extreme values.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 2/4/2019 3:14 AM 86. The following data represent scores on a 15-point aptitude test: 8, 10, 15, 12, 14, and 13.

a. Compute the sample mean for the original data.

Subtract 5 from every observation and complete the sample mean for the new data.

Chapter 02 - Describing Data with Numerical Measures

b. Compute the sample variance for the original data. Round your answer to one decimal place.

Subtract 5 from every observation and complete the sample variance for the new data.

c. What effect, if any, does subtracting 5 from every observation have on the sample mean and sample variance?

ANSWER:

12; 7; 6.8; 6.8; The sample mean is shifted to the left (decreased by 5), but the sample variance remains unchanged.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 3/18/2019 4:40 AM 87. Thirty-three students were asked to rate themselves on whether they were outgoing or not using this five-

point scale: 1 = extremely extroverted, 2 = extroverted, 3 = neither extroverted nor introverted, 4 = introverted, or 5 = extremely introverted. The results are shown in the table below:

a. Calculate the sample mean. Round your answer to two decimal places.

b. Calculate the median. Round your answer to two decimal places.

c. Calculate the sample standard deviation. Round your answer to two decimal places.

ANSWER:

2.88; 3; 0.70

POINTS: QUESTION TYPE:

1 Subjective Short Answer

Chapter 02 - Describing Data with Numerical Measures HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 3/18/2019 4:54 AM 88. The following data represent the number of small cracks per bar for a sample of eight steel bars:

4 6 10 1 3 1 25 8 a. Find the average number of small cracks per bar. Round your answer to two decimal places.

b. Find the standard deviation for the number of small cracks per bar. Round your answer to two decimal places.

ANSWER:

7.25; 7.85

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 3/18/2019 6:24 AM 89. Twenty-eight applicants interested in working for the Food Stamp program took an examination designed to

measure their aptitude for social work. A stem and leaf plot of the 28 scores appears below, where the first column is the count per branch, the second column is the stem value, and the remaining digits are the leaves.

a. What is the median score? Round your answer to two decimal places.

b. What is the sample mean for this data set? Round your answer to two decimal places.

c. What is the value of the sample standard deviation? Round your answer to two decimal places.

Chapter 02 - Describing Data with Numerical Measures

d. What is the range of this data? Round your answer to two decimal places.

ANSWER:

84.50; 80.64; 12.85; 52.00

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 3/18/2019 6:29 AM 90. Suppose you are given the following set of sample measurements:

–1, 0, 2, 6, 5, 6 a. Calculate the sample mean. Round your answer to one decimal place.

b. Find the median. Round your answer to one decimal place.

c. Find the mode. Round your answer to one decimal place.

d. Calculate the sample variance. Round your answer to one decimal place.

e. Calculate the sample standard deviation. Round your answer to one decimal place.

f. Calculate the range. Round your answer to one decimal place.

g. Is this data symmetric, skewed to the right or skewed to the left?

Justify your answer.

ANSWER:

3; 3.5; 6; 9.6; 3.1; 7; Skewed to the left; The data is skewed to the left since the mean is less than the median.

Chapter 02 - Describing Data with Numerical Measures POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 3/18/2019 6:34 AM 91. A neighborhood ice cream vendor reports the following sales of single scoop ice cream cones (measured in

hundreds of cones) for five randomly selected weeks: 54653 a. Find the average number of weekly sales of single scoop ice cream cones. Round your answer to one decimal place.

b. Find the median number of weekly sales of single scoop ice cream cones. Round your answer to one decimal place.

c. Find the variance for the weekly sales of single scoop ice cream cones. Round your answer to one decimal place.

ANSWER:

4.6; 5; 1.3

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 3/28/2019 2:19 AM 92. The following data represent the sales (measured in $10,000) of seven real estate salespersons employed by

a local agency: 23 34 56 47 45 60 249 Which measure of center, the mean or the median, would provide a better measure of the average sales of the company?

Explain.

ANSWER:

Median; The median would seem to provide a better measure of the average sales

Chapter 02 - Describing Data with Numerical Measures

since it will not be adversely affected by the extreme value of 249. (The mean will be pulled strongly to the right by the extreme value of 249.) POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 3/28/2019 2:31 AM 93. The following data represent the number of calories in 12-ounce cans of eight popular soft drinks:

124 144 147 146 148 154 150 234 a. Find the median. Round your answer to one decimal place.

b. Find the sample mean. Round your answer to one decimal place.

c. Based on the values in parts (a) and (b) above, are the measurements symmetric, skewed to the right, or skewed to the left?

Explain.

ANSWER:

147.5; 155.9; Skewed right; Since the mean is larger than the median, we conclude that the measurements are skewed to the right.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 3/28/2019 2:36 AM 94. In a psychological experiment, the time on task was recorded for ten subjects under a 5-minute time

constraint. These measurements are in seconds: 182 197 207 272 192 257 247 197 232 237 a. Find the average time on task.

b. Find the median time on task. Round your answer to one decimal place.

Chapter 02 - Describing Data with Numerical Measures

c. If you were writing a report to describe these data, which measure of central tendency would you use?

Explain.

ANSWER:

222; 219.5; Mean; Since there are no unusually large or small observations to affect the value of the mean, we would probably report the mean or average time on task.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 3/28/2019 4:07 AM 95. You are given n = 8 measurements: 13, 11, 15, 16, 14, 14, 13, and 15.

Calculate the range.

Calculate the sample mean. Round your answer to three decimal places.

Calculate the sample variance. Round your answer to three decimal places.

Calculate the standard deviation. Round your answer to three decimal places.

Compare the range and the standard deviation. The range is approximately how many standard deviations? Round your answer to three decimal places.

ANSWER:

5; 13.875; 2.411; 1.553; 3.220

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic

Chapter 02 - Describing Data with Numerical Measures DATE CREATED: DATE MODIFIED:

2/4/2019 3:14 AM 3/28/2019 4:06 AM

96. A sample of n = 10 measurements consists of the following values:

15, 12, 13, 16, 11, 12, 14, 15, 11, 13 a. Find the mean. Round your answer to one decimal place.

b. Find the median.

c. Based on the values in parts (a) and (b) above, are the measurements symmetric, skewed to the right, or skewed to the left?

Explain.

d. Find the standard deviation. Round your answer to two decimal places.

e. Find the range.

f. Use the range to approximate s. Round your answer to two decimal places.

g. Is this a good approximation?

ANSWER:

13.2; 13; Skewed to the right; Since the mean is slightly larger than the median, we conclude that the measurements are slightly skewed to the right.; 1.75; 5; 1.25; Yes

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 3/28/2019 4:05 AM

Chapter 02 - Describing Data with Numerical Measures 97. The following data represent the scores for a sample of 10 students on a 20-point chemistry quiz:

16 14 2 8 12 12 9 10 15 13 a. Calculate the median.

b. Calculate the sample mean. Round your answer to one decimal place.

c. Calculate the sample variance. Round your answer to three decimal places.

ANSWER:

12; 11.1; 16.767

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 3/28/2019 4:05 AM 98. Assume that all employees of a community college received a $150 monthly raise.

a. How would this affect the mean of salaries?

b. How would this affect the standard deviation of salaries?

ANSWER:

The mean will increase by $150; The standard deviation will remain unchanged

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 2/4/2019 3:14 AM 99. The following values denote the number of customers handled by an optometrist during a random sample of

four periods of one hour each: 4, 6, 2, and 5. a. Find the standard deviation of these values. Round your answer to three decimal places.

Chapter 02 - Describing Data with Numerical Measures

b. Find the range, R.

ANSWER:

1.708; 4

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:14 AM DATE MODIFIED: 3/28/2019 4:04 AM 100. Tchebysheff's Theorem states that: Given a number k greater than or equal to 1, and a set of measurements,

at least [1 – (1/k2)] of the measurements in the data set will lie within k standard deviations of their mean. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 3/28/2019 4:22 AM 101. The Empirical Rule states that: Given a distribution of measurements that is approximately bell-shaped

(mound-shaped), then the interval contains approximately 68% of the measurements, the interval contains approximately 95% of the measurements, and the interval contains approximately 99.7% of the measurements. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 3/28/2019 4:26 AM 102. The Empirical Rule and Tchebysheff's Theorem can be used to describe data sets. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False

Chapter 02 - Describing Data with Numerical Measures DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 103. The Empirical Rule can be applied to any numerical data set. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 104. For larger sample sizes, a rough approximation for the sample standard deviation s is that s ≈ R / 4, where R

is the range. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 105. Since Tchebysheff's Theorem applies to any distribution, it is very conservative. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 106. Tchebysheff's Theorem gives a lower bound to the fraction of measurements to be found in an interval

constructed as

, where

is a sample mean and s is a sample standard deviation.

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 3/28/2019 4:58 AM

Chapter 02 - Describing Data with Numerical Measures 107. Tchebysheff's Theorem applies only to data sets that have a mound-shaped distribution. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 108. While Tchebysheff's Theorem applies to any distribution, regardless of shape, the empirical rule applies

only to distributions that are mound-shaped. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 109. The mean of forty sales receipts is $69.75 and the standard deviation is $10.25. Using Tchebysheff's

Theorem, at least 75% of the sales receipts were between $49.25 and $90.25. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 110. According to Tchebysheff's Theorem, at least 96% of observations should fall within 5 standard deviations

of the mean. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 111. Tchebysheff's Theorem provides us with a measure of shape that focuses on the difference between the

Chapter 02 - Describing Data with Numerical Measures

mode and the mean and then relates it to the standard deviation. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 112. The distribution of checking account balances for customers at Independent Bank is known to be mound-

shaped with a mean of $1,800 and a standard deviation of $300. Given this information, the percentage of accounts with balances between $1,500 and $2,100 will be approximately 95%. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 3/28/2019 6:20 AM 113. The distribution of dollars paid for home insurance by home owners in Detroit is mound-shaped with a

mean equal to $800 every six months, and a standard deviation equal to $120. Based on this information, we can use Tchebysheff's Theorem to determine the percentage of home owners that will pay between $560 and $1,040 for home insurance. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 3/28/2019 6:24 AM 114. The distribution of credit card balances for customers is highly skewed to the right with a mean of $1,200

and a standard deviation of $150. Based on this information, approximately 68% of the customers will have credit card balances between $1,050 and $1,350. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM

Chapter 02 - Describing Data with Numerical Measures DATE MODIFIED: 2/4/2019 3:24 AM 115. A college placement office conducted a survey of 100 engineers who had graduated from Stanford

University. For these engineers, the mean salary was computed to be $72,000 with a standard deviation of $8,000. The percentage of these engineers who earn more than $96,000 or less than $48,000 is: a. approximately 0% b. at least 5.6% (1/18 of the engineers) c. at most 5.6% (1/18 of the engineers) d. at most 11.1% (1/9 of the engineers) e. at least 11.1% (1/9 of the engineers) ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 116. From a sample of size 100, the following descriptive measures were calculated: median = 23, mean = 20,

standard deviation = 5, range = 35; seventy-five sample values are between 10 and 30; and ninety-nine sample values are between 5 and 35. If you knew the sample mean, median, and standard deviation were correct, which one of the following conclusions might you draw? a. The distribution is skewed to the right because the median exceeds the mean. b. The range must have been calculated incorrectly because it should not be seven times the standard

deviation value. c. The number of sample values between 10 and 30 was miscounted. d. The number of sample values between 5 and 35 must have been miscounted because all 100 values must be in this interval. e. All of these. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 3/28/2019 6:26 AM 117. Tchebysheff's Theorem states that the percentage of measurements in a data set that fall within three

standard deviations of their mean is: a. 75% b. 68% c. 16% d. at least 89% e. at most 80% ANSWER:

Chapter 02 - Describing Data with Numerical Measures POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 118. Given a distribution of measurements that is approximately mound-shaped, the Empirical Rule states that

the approximate percentage of measurements in a data set that fall within two standard deviations of their mean is approximately: a. 99% b. 95% c. 90% d. 68% e. 75% ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 119. The expression , where is recognizable as the formula for: a. the population mean, computed from ungrouped data b. the sample mean, computed from ungrouped data c. the population mean, computed from grouped data d. the sample mean, computed from grouped data e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM

120. The expression

is recognizable as the formula for:

a. the sample variance, computed from ungrouped data b. the population variance, computed from ungrouped data c. the sample variance, computed from grouped data d. the population variance, computed from grouped data e. the population variance, computed from ungrouped or grouped data ANSWER: c POINTS: 1

Chapter 02 - Describing Data with Numerical Measures QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 121. Whenever a statistical population can be described, at least roughly, by the perfectly symmetrical, mound-

shaped normal curve, we can estimate the percentages of all population values that lie within specified numbers of standard deviations from the mean with the help of: a. Tchebysheff's Theorem b. the empirical rule c. the interquartile range d. box plot e. Tchebysheff's Theorem or the empirical rule ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 3/28/2019 6:34 AM 122. The lengths of screws produced by a machine are normally distributed with a mean of 3 inches and a

standard deviation of .2 inches. Therefore, we know: a. that approximately 68 percent of all screws have lengths between 2.8 and 3.2 inches b. that approximately 95 percent of all screws have lengths between 2.8 and 3.2 inches c. that just about all screws have lengths between 2.8 and 3.2 inches d. that approximately 98 percent of all screws have lengths between 2.8 and 3.2 inches e. none of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 123. According to Tchebysheff's Theorem, provided only a number

, regardless of the shape of a population's frequency distribution. The proportion of observations falling within k standard deviations of the mean is: a. at most (1 – 1/k)2 b. at least (1 – 1/k)2 c. at most 1 – (1/k2) d. at least 1 – (1/k2)

Chapter 02 - Describing Data with Numerical Measures e. exactly 1 – (1/k2) ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 3/28/2019 6:41 AM 124. The distribution of actual weight of tomato soup in a 16-ounce can is thought to be mound-shaped with a

mean equal to 16 ounces, and a standard deviation equal to 0.25 ounces. Based on this information, between what two values could we expect 95% of all cans to weigh? a. 15.75 to 16.25 ounces b. 15.50 to 16.50 ounces c. 15.25 to 16.75 ounces d. 15 to 17 ounces e. 15 to 16 ounces ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 3/28/2019 6:43 AM 125. Incomes of workers in an automobile company in Michigan are known to be right-skewed with a mean

equal to $36,100. If at least 8/9 of all incomes are in the range of $29,500 to $42,700, and this was based on Tchebysheff's Theorem, what is the standard deviation for the auto workers? a. $6,500 b. $6,700 c. Approximately $4,755 d. $2,200 e. $2,600 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 3/28/2019 6:51 AM 126. When a machine dispensing cola at a bottling plant is working correctly, it dispenses a mean of 12 ounces

of cola per bottle with a standard deviation of 0.2 ounces. a. When the machine is working correctly, what percentage of the bottles will be filled with between 11.6 and 12.4 ounces of cola?

Chapter 02 - Describing Data with Numerical Measures

At least

b. On a particular day, the bottling plant supervisor randomly selects two bottles from among those filled by the machine. One bottle contains 11.8 ounces of cola, and the other contains 12.1 ounces of cola. Based on the contents of these two bottles, what can the supervisor infer (conclude) about the machine's performance?

ANSWER:

0.75; The machine is working correctly

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 127. A new manufacturing plant has 20 job openings. To select the best 20 applicants from among the 1,000 job

seekers, the plant's personnel office administers a written aptitude test to all applicants. The average score on the aptitude test is 150 points with a standard deviation of 10 points. Assume the distribution of test scores is approximately mound-shaped. a. What percentage of the test scores will fall between 130 and 170 points? Approximately .............................. (Enter as a decimal percent or use the % sign.) b. How many applicants will score between 130 and 170 points? At least

applicants.

c. One of the applicants scored 192 points on the test. What might you conclude about this test score?

ANSWER:

75%; 750; The score should be regarded as an outlier.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 3/28/2019 7:34 AM 128. Thirty-three students were asked to rate themselves on whether they were outgoing or not using this five-

point scale: 1 = extremely extroverted, 2 = extroverted, 3 = neither extroverted nor introverted, 4 = introverted, or 5 = extremely introverted. The results are shown in the table below:

Chapter 02 - Describing Data with Numerical Measures

a. Find the percentage of measurements in the following intervals: = = This interval contains approximately

% of the data.

= = This interval contains approximately

% of the data.

b. Comment on the shape of the distribution.

ANSWER:

2.18; 3.58; 68; 1.49; 4.27; 95; The data are approximately mound-shaped

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 3/28/2019 7:55 AM 129. Given the following frequency table:

a. What fraction of the x values fall within two standard deviations of the mean?

Within three standard deviations of the mean?

b. Do the results of part (a) agree with Tchebysheff 's Theorem?

Chapter 02 - Describing Data with Numerical Measures

ANSWER:

0.95; 0.96; Yes

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/10/2019 6:36 AM 130. Suppose the hourly dollar amount of food sold by a Burger King franchise follows an approximately

mound-shaped distribution with a mean sales level of $400 per hour and a standard deviation of $60 per hour. a. What percentage of the working hours does this Burger King franchise sell between $280 and $520 worth of food per hour?

b. Suppose yesterday, during a one-hour period, this Burger King franchise had sales at the 84th percentile. What dollar sales figure does this represent?

ANSWER:

95%; $460

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 131. Twenty-eight applicants interested in working for the Food Stamp program took an examination designed

to measure their aptitude for social work. A stem and leaf plot of the 28 scores appears below, where the first column is the count per "branch," the second column is the stem value, and the remaining digits are the leaves.

a. Should the Empirical Rule be applied to this data set?

Chapter 02 - Describing Data with Numerical Measures

b. Use the range approximation to determine an approximate value for the standard deviation.

ANSWER:

No; 13

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/10/2019 6:36 AM 132. The following data represents the number of minutes an athlete spends training per day.

73 74 76 77 79 79 83 84 88 84 84 85 86 86 87 87 88 91 92 92 93 97 98 98 81 82 The mean and standard deviation were computed to be 85.54 and 6.97, respectively. a. What percentage of measurements would you expect to be between 71.60 and 99.48? If the data is approximately mound-shaped, use the Empirical Rule to make a prediction.

b. What percentage of the measurements lies in the interval (71.60, 99.48)?

ANSWER:

95%; 100%

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/10/2019 8:03 AM 133. For Labrador Retriever dogs, the average weight at 12 months of age is 50 pounds with a standard

deviation of 2.5 pounds. What can be said about the proportion of 12 month old Labrador Retrievers that will weigh between 46.25 pounds and 53.75 pounds? Choose the appropriate rule: Approximately what proportion of weights will fall into the interval described above? If necessary, round your answer to two decimal places.

Explain.

Chapter 02 - Describing Data with Numerical Measures

ANSWER:

Tchebysheff's Theorem; 0.56; Using Tchebysheff's Theorem, since the given interval represents 1.5 standard deviations on each side of the mean, at least 1 1/(1.5)^2=0.56 of the weights will lie in the interval.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/4/2019 3:39 AM 134. A sample of n = 10 measurements consists of the following values:

15 12 13 16 11 12 14 15 11 13 a. Can you use Tchebysheff's Theorem to describe this data set?

Why or why not?

b. Can you use the Empirical Rule to describe this data set?

Why or why not?

ANSWER:

Yes; Tchebysheff's Theorem applies to any set of measurements; No; The data is not mound-shaped

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/4/2019 10:03 AM 135. A distribution of measurements is relatively mound-shaped with mean 70 and standard deviation 10.

a. What proportion of the measurements will fall between 60 and 80?

b. What proportion of the measurements will fall between 50 and 90?

Chapter 02 - Describing Data with Numerical Measures

c. What proportion of the measurements will fall between 50 and 80?

d. If a measurement is chosen at random from this distribution, what is the probability that it will be greater than 80?

ANSWER:

68%; 95%; 81.5%; 16%

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/5/2019 2:45 AM 136. A sample of basketball players has a mean height of 75 inches and a standard deviation of 5 inches. You

know nothing else about the size of the data or the shape of the data distribution. Which rule(s) can you use to describe the data?

Explain.

Approximately what proportion of measurements will fall between 60 and 90?

Approximately what proportion of measurements will fall between 65 and 85?

Approximately what proportion of measurements will fall below 65?

ANSWER:

Tchebysheff's Theorem; Since nothing is known about the shape of the distribution, you must use Tchebysheff's Theorem to describe the data.; at least ; at least ; at most

POINTS: QUESTION TYPE:

1 Subjective Short Answer

Chapter 02 - Describing Data with Numerical Measures HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/5/2019 5:36 AM 137. A random sample of 100 foxes was examined by a team of veterinarians to determine the prevalence of a

particular type of parasite. Counting the number of parasites per fox, the veterinarians found that 65 foxes had no parasites, 20 had one parasite, and so on. A frequency tabulation of the data is given here:

What fraction of the parasite counts fall within two standard deviations of the mean?

Within three standard deviations?

Do these results agree with Tchebysheff's Theorem?

ANSWER:

0.95; 0.96; Yes

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/10/2019 6:46 AM 138. In a time study, conducted at a manufacturing plant, the length of time to complete a specified operation is

measured for each on n = 40 workers. The mean and standard deviation are found to be 15.2 and 1.40, respectively. a. Describe the sample data using the Empirical Rule.

b. Describe the sample data using Tchebysheff's Theorem.

ANSWER:

If the distribution of measurements is mound-shaped, you can apply the Empirical Rule and expect approximately 68% of the measurements to fall into the interval from 13.8 to 16.6, approximately 95% to fall into the interval from 12.4 to 18.0, and approximately 99.7% to fall into the interval from 11.0 to 19.4.; If you doubt that the distribution of measurements is mound-shaped, or if you wish for some

Chapter 02 - Describing Data with Numerical Measures

other reason to be conservative, you can apply Tchebysheff's Theorem and be absolutely certain of your statements. Tchebysheff's Theorem tells you that at least 3/4 of the measurements fall into the interval from 12.4 to 18.0 and at least 8/9 into the interval from 11.0 to 19.4. POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/9/2019 5:30 AM 139. An analytical chemist wanted to use electrolysis to determine the number of moles of cupric ions in a given

volume of solution. The solution was partitioned into n = 30 portions of 0.2 milliliter each. Each of the n = 30 portions was tested. The average number of moles of cupric ions for the n = 30 portions was found to be 0.185 mole; the standard deviation was 0.015 mole. Calculate the following intervals:

Describe the distribution of the measurements for the n = 30 portions of the solution using Tchebysheff's Theorem.

Describe the distribution of the measurements for the n = 30 portions of the solution using the Empirical Rule.

ANSWER:

(0.170, 0.200); (0.155, 0.215); (0.140, 0.230); If we doubt that the distribution of measurements is mound-shaped, or if no prior information as to the shape of the distribution is available, we use Tchebysheff's Theorem. We would expect 0 of the measurements to fall in the interval 0.17 to 0.20; at least 3/4 of the measurements to fall in the interval 0.155 to 0.215, and at least 8/9 of the measurements to fall in the interval from 0.14 to 0.23.; According to the Empirical Rule, we would expect approximately 68% of the measurements to fall in the interval 0.17 to 0.20, approximately 95% of the measurements to fall in the interval 0.155 to 0.215, and all or almost all the measurements to fall in the interval 0.14 to 0.23.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM

Chapter 02 - Describing Data with Numerical Measures DATE MODIFIED:

4/10/2019 6:51 AM

140. The times required to service customers' cars at a repair shop are skewed to the right with a mean of 2.5

hours and a standard deviation of 0.75 hours. What can be said about the proportion of cars whose service time is either less than one hour or more than four hours? ANSWER: Applying the Tchebysheff 's Theorem, we can say that at most 25% of the cars take less than one hour or more than four hours to service. POINTS: 1 QUESTION TYPE: Essay HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 141. The mean and variance of a sample of n = 25 measurements are 80 and 100, respectively. Explain in detail

how to use Tchebysheff's Theorem to describe the distribution of measurements. ANSWER: The distribution of measurements is centered about 80, and Tchebysheff's Theorem states: At least 3/4 of the 25 measurements lie within 2 SD of the mean, that is, between 60 to 100. At least 8/9 or of the measurements lie within 3 SD of the mean, that is, between 50 to 110. POINTS: 1 QUESTION TYPE: Essay HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM

142. The sample z-score is a measure of relative standing defined by:

between an observation and the mean in units of the standard deviation. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/9/2019 6:20 AM 143. z-scores exceeding 3 in absolute value are likely to occur. a. True b. False ANSWER: False POINTS: 1

. It measures the distance

Chapter 02 - Describing Data with Numerical Measures QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 144. Any unusually large observation (as measured by a z-score greater than 3), or any unusually small

observation (as measured by a z-score smaller than −3) is considered an outlier. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/17/2019 12:59 PM 145. The 10th percentile of a set of measurements is the value which exceeds 90% of the measurements and is

less than the remaining 10% of the measurements. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/9/2019 6:24 AM 146. The difference between the largest and smallest values in an ordered array is called the interquartile range. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 147. Quartiles divide the values in a data set into four parts of equal size. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False

Chapter 02 - Describing Data with Numerical Measures DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 148. The interquartile range is the difference between the upper and lower quartiles. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/9/2019 6:29 AM 149. Expressed in percentiles, the upper quartile is the 75th percentile. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/9/2019 6:31 AM 150. Measures of relative standing indicate the position of one observation relative to other observations in a set

of data. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 151. The median equals the second quartile. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 152. The standard deviation is a measure of relative standing.

Chapter 02 - Describing Data with Numerical Measures a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 153. If a set of data has 120 values, the value of the 30th percentile will be calculated using the 36th and 37th

values in the data, when the data values have been arranged in ascending order. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/9/2019 6:33 AM 154. The distribution of a set of data is considered to be symmetric if the mean and the second quartile are equal. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/10/2019 8:00 AM 155. If the mean value of a set of data is 83.5 and the median is 72.8, then the third quartile will be at least 83.5. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 156. Assume that 75% of the households in Michigan have incomes of $24,375 or below. Given this

information, it is certain that the mean household income is less than $24,375. a. True b. False

Chapter 02 - Describing Data with Numerical Measures ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 157. The left and right ends of the box in a box and whisker plot represent the 25th and 75th percentiles,

respectively. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/9/2019 7:03 AM 158. The following five-number summary for a sample of size 500 were obtained: Minimum = 250,

and Maximum = 4,950. Based on this information, if you were to construct a box and whisker plot, the value 215 is considered an outlier. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 159. The following five-number summary for a sample of size 500 were obtained: Minimum = 250,

and Maximum = 4,950. Based on this information, if you were to construct a box and whisker plot, the value corresponding to the right-hand edge of the box would be 4,800. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/17/2019 1:15 PM 160. The following five-number summary for a sample of size 500 were obtained: Minimum = 250,

and Maximum = 4,950. Based on this information, the distribution of the data

Chapter 02 - Describing Data with Numerical Measures

seems to be symmetric. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 161. The following five-number summary for a sample of size 500 were obtained: Minimum = 250,

and Maximum = 4,950. Based on this information, if you were to construct a box and whisker plot, the value corresponding to the upper fence is 10,200. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 162. A sample of 2,500 vehicles in Minnesota showed the following statistics related to the number of accidents

per month: skewed.

Based on these data, we can infer that the distribution of accidents is

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/17/2019 1:19 PM 163. Which of the following randomly selected measurements, x, might be considered a potential outlier (i.e., an

unusual measurement) if it was selected from the given population? a. x = 0 from a population with = 0 and = 2 b. x = −5 from a population with = 1 and = 4 c. x = 7 from a population with = 3 and d. x = 4 from a population with = 0 and

=2 =1 e. x = 1 from a population with = 0 and = 2 ANSWER: POINTS:

d 1

Chapter 02 - Describing Data with Numerical Measures QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/9/2019 7:48 AM 164. Which one of the values below represents a lower quartile for the data set 23, 24, 21, and 20? a. 22.0 b. 22.5 c. 20.25 d. 23.5 e. none of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 165. Which one of the values below represents the upper quartile of the data set 10, 12, 16, 7, 9, 7, 41, and 14? a. 8 b. 15.5 c. 7 d. 24 e. 10 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 166. Expressed in percentiles, the interquartile range is the difference between the: a. 80% and 20% values b. 95% and 45% values c. 75% and 25% values d. 70% and 20% values e. 90% and 10% values ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM

Chapter 02 - Describing Data with Numerical Measures DATE MODIFIED: 4/9/2019 7:53 AM 167. A student took a chemistry exam where the exam scores were mound-shaped with a mean score of 90 and a

standard deviation of 64. She also took a statistics exam where the scores were mound-shaped, the mean score was 70 and the standard deviation was 16. If the student's grades were 102 on the chemistry exam and 77 on the statistics exam, then: a. the student did relatively better on the chemistry exam than on the statistics exam, compared to the other students in each class. b. the student did relatively better on the statistics exam than on the chemistry exam, compared to the other students in the two classes. c. the student's scores on both exams are comparable, when accounting for the scores of the other students in the two classes. d. it is impossible to say which of the student's exam scores indicates the better performance. e. the student did relatively the same on both exams. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 168. Which of the following summary measures is affected most by outliers? a. the first quartile b. the second quartile c. the third quartile d. the interquartile range e. the mean ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/10/2019 7:43 AM 169. An exam is given to both the fourth period class and the sixth period class. If a student's score is at the 30th

percentile in the fourth period class but at the 60th percentile in the sixth period class, which one of the following statements is true? a. Students in the sixth period class generally performed better on the exam than the students in the

fourth period class. b. A person whose score is at the 15th percentile in the fourth period class will have a score at the 30th percentile in the sixth period class. c. A person whose score is at the 70th percentile in the sixth period class will have a score at the 40th percentile in the fourth period class.

Chapter 02 - Describing Data with Numerical Measures d. Students in the fourth period class generally performed better on the exam than students in the sixth

period class. e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/9/2019 9:01 AM 170. The percentage of all observations in a data set that lies between the 30th percentile and the third quartile: a. equals 30 b. equals 45 c. equals 75 d. equals 85 e. cannot be determined without additional information ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/17/2019 1:44 PM 171. A graphical device that highlights the highest and lowest values in a data set, along with a number of other

key observations in an ordered array of the data, such as the upper quartile, the middle value (or median), and the lower quartile, is called: a. a boxplot b. a five-number summary c. a dotplot d. a stem-and-leaf plot e. a histogram ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 172. Lily recently took a biochemistry test, and it was reported back to her that her score placed her at the 97th

percentile. Therefore: a. Lily's score has a z-score of 0.97 b. Lily was in the bottom 3% of the students who took the test

Chapter 02 - Describing Data with Numerical Measures c. Lily scored as high or higher than 97% of the students who took the test d. ninety-seven students who took the test scored below Lily e. ninety-seven students who took the test scored the same as Lily ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/9/2019 9:04 AM 173. A sample of 50 values produced the following summary statistics:

Based on this information, the left and right ends of the box in a box and whisker plot are, respectively, a. 10 and 14.6 b. 14.6 and 16.7 c. 10 and 16.7 d. 5.3 and 32.0 e. none of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/17/2019 1:53 PM 174. A sample of 600 values produced the following summary statistics:

Based on this information, the lower fence on a box and whisker plot is: a. 26.80 b. −4.60 c. 75.80 d. 102.60 e. 56.8 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/17/2019 1:53 PM 175. A sample of 600 values produced the following summary statistics:

Chapter 02 - Describing Data with Numerical Measures

Based on this information, upper fence on a box and whisker plot is: a. 26.80 b. −4.60 c. 75.80 d. 102.60 e. 62.4 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/17/2019 1:53 PM 176. If a data set has 15 values that have been sorted in ascending order, which value in the data set will be the

25th percentile? a. the fourth value b. the third value c. the second value d. the first value e. There is not enough information to answer this question. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/9/2019 9:11 AM 177. If the distribution of sales is thought to be symmetric with very little variation, then: a. the whiskers on a box and whisker plot should be about half as long as the box is wide b. the width of the box in a box and whisker plot will be very wide but the whisker will be very short c. the left and right edges of the box in a box and whisker plot will be approximately equal distance

from the second quartile d. all of the above e. none of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/17/2019 1:57 PM

Chapter 02 - Describing Data with Numerical Measures 178. The following summary statistics were computed from a sample of size 250:

. Based on this information, which of the following statements is correct? a. The distribution of the data is slightly right-skewed. b. The distribution of the data is symmetric. c. A data value of 20 is an outlier. d. All of the above. e. None of these. ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/17/2019 1:58 PM 179. The following data represent the number of small cracks per bar for a sample of eight steel bars:

4 6 10 1 3 1 25 8 Which, if any, of the observations appear to be outliers? Justify your answer.

ANSWER:

The value 25 has a z-score of 2.26 making it a suspect outlier.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 180. Attendance at London Symphony concerts for the past two years showed an average of 3,000 people per

performance with a standard deviation of 100 people per performance. Attendance at a randomly selected concert was found to be 3,290. If attendance data is mound-shaped, does the attendance at the selected concert appear to be unusual?

Justify your conclusion.

ANSWER:

Yes; The z-score associated with 3,290 is 2.90, indicating that 3,290 is 2.90 standard deviations above the mean. Although the z-score does not exceed 3, it is close enough for one to suspect that 3,290 is an outlier.

POINTS: QUESTION TYPE:

1 Subjective Short Answer

Chapter 02 - Describing Data with Numerical Measures HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 181. Consider the following set of measurements: 6, 3, 5, 14, 2, 6, 0, and 8.

a. Find the 25th percentile: , Find the 50th percentile: , Find the 75th percentile: . b. What is the value of the interquartile range? ANSWER:

2.25; 5.5; 7.5; 5.25

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/9/2019 9:15 AM 182. Consider the following set of measurements:

5.4, 5.9, 3.5, 4.1, 4.6, 2.5, 4.7, 6.0, 5.4, 4.6, 4.9, 4.6, 4.1, 3.4, 2.2 You may use the Data Analysis tool if you want. a. Find the 25th percentile: , Find the 50th percentile: , Find the 75th percentile: . b. What is the value of the interquartile range? ANSWER:

3.5; 4.6; 5.4; 1.9

Chapter 02 - Describing Data with Numerical Measures POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/9/2019 9:45 AM 183. Twenty-eight applicants interested in working for the Food Stamp program took an examination designed

to measure their aptitude for social work. A stem-and-leaf plot of the 28 scores appears below, where the first column is the count per branch, the second column is the stem value, and the remaining digits are the leaves.

What is the value of the first quartile? Q1 = What is the value of the third quartile? Q3 = What is the interquartile range? IQR = Find the lower fence.

Find the upper fence.

Construct a boxplot for this data.

Does the boxplot indicate the presence of any outliers?

Chapter 02 - Describing Data with Numerical Measures

ANSWER:

70.5; 90.25; 19.75; 40.875; 119.875

No POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/10/2019 3:49 AM 184. The following data represent the number of calories in 12 ounce cans of eight popular soft drinks:

124 144 147 146 148 154 150 234 Find the lower fence.

Find the upper fence.

Construct a boxplot for this data. Does the boxplot indicate the presence of any outliers? ANSWER:

131.75; 165.75

Chapter 02 - Describing Data with Numerical Measures

Yes POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/10/2019 4:17 AM 185. The following data represent the scores for a sample of 10 students on a 20-point chemistry quiz:

16 14 2 8 12 12 9 10 15 13 Calculate the z-score for the smallest and largest observations. Smallest: Largest:

Is either of these observations unusually large or unusually small?

ANSWER:

-2.222; 1.197; Yes

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 4/10/2019 4:30 AM 186. Two students are enrolled in different sections of an introductory statistics class at a local university. The

first student, enrolled in the morning section, earns a score of 76 on a midterm exam where the class mean was 64 with a standard deviation of 8. The second student, enrolled in the afternoon section, earns a score of 72 on a midterm exam where the class mean was 60 with a standard deviation of 7.5. If the scores on the midterm exams are normally distributed, which student scored better relative to his or her classmates?

Chapter 02 - Describing Data with Numerical Measures

Explain. ANSWER:

The second student; The student in the afternoon section scored better relative to his/her classmates since that student's z-score is larger.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 187. If the 90th and 91st observations in a set of 100 data values are 158 and 167, respectively, then the 90th

percentile value is: ANSWER:

166.1

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM 188. If the 18th and 19th observations in a set of 25 data values are 42.6 and 43.8, then the 70th percentile value

is: ANSWER:

42.84

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:24 AM DATE MODIFIED: 2/4/2019 3:24 AM

Chapter 03 - Describing Bivariate Data 1. If the correlation coefficient , then all the data points lie exactly on a straight line. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 2/4/2019 3:33 AM 2. The correlation coefficient r is a number that indicates the direction and the strength of the relationship

between the dependent variable y and the independent variable x. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 2/4/2019 3:33 AM 3. If the correlation coefficient

, then there is no linear relationship whatsoever between the dependent variable y and the independent variable x. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 2/4/2019 3:33 AM 4. A perfect straight line sloping upward would produce a correlation coefficient equal to +1. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 3/28/2019 9:41 AM 5. A perfect straight line sloping downward would produce a correlation coefficient equal to –1. a. True

Chapter 03 - Describing Bivariate Data b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 3/28/2019 9:42 AM 6. The standard deviation is a measure of the linear relationship between two quantitative variables. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 2/4/2019 3:33 AM 7. Generally speaking, if two quantitative variables are unrelated, the covariance will be a positive or negative

number close to zero. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 2/4/2019 3:33 AM 8. The best-fitting line relating the dependent variable y to the independent variable x, often called the regression

or least-squares line, is found by minimizing the sum of the squared differences between the data points and the line itself. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 3/29/2019 4:22 AM 9. The scatterplot is a graph that is used to graphically represent the relationship between two quantitative

variables. a. True b. False

Chapter 03 - Describing Bivariate Data ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 2/4/2019 3:33 AM 10. When constructing a scatterplot, the independent variable (x) is placed on the horizontal axis, and the

dependent variable (y) is placed on the vertical axis. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 2/4/2019 3:33 AM 11. A scatterplot is not particularly useful in determining if the relationship between the independent and

dependent variables is not linear. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 2/4/2019 3:33 AM 12. If the linear relationship between the dependent and independent variables is positive, the scatterplot will

show the data points on the (x, y) plane generally moving from the lower left corner to the upper right corner. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 2/4/2019 3:33 AM 13. Assume that the sample standard deviations for the variables x and y are different. If the correlation

coefficient between the independent variable x and the dependent variable y is 0.87, then the best-fitting line would have a slope equal to 0.87. a. True b. False

Chapter 03 - Describing Bivariate Data ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 3/29/2019 4:26 AM 14. If two variables have a correlation coefficient equal to 0.005, this means that there is no relationship between

the two variables whatsoever. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 3/28/2019 10:07 AM 15. A perfect correlation between two variables will always produce a correlation coefficient of +1.0. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 2/4/2019 3:33 AM 16. Which of the following are measures of the linear relationship between two variables? a. the covariance b. the correlation coefficient c. the variance d. both the covariance and the correlation coefficient e. both the correlation coefficient and the variance ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 2/4/2019 3:33 AM 17. Generally speaking, if two variables are unrelated (as one increases, the other shows no pattern), the

covariance will be: a. a large positive number

Chapter 03 - Describing Bivariate Data b. a large negative number c. a positive or negative number close to zero d. a positive or negative number close to 100 e. none of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 2/4/2019 3:33 AM 18. Given the least-squares regression line y = 3.8 – 2x, a. the relationship between x and y is positive b. the relationship between x and y is negative c. there is no linear relationship between x and y d. as x decreases, so does y e. as x increases, so does y ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 3/28/2019 10:10 AM 19. Given that a. 0.70

= 400, = 625,

= 350, and n = 10, the correlation coefficient is:

b. 0.56 c. 0.875 d. 0.156 e. 0.141 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 2/4/2019 3:33 AM 20. If a regression line has a y-intercept of 6.75 and a slope of 1.25, then when x = 2 the actual value of y is: a. 9.25 b. 8.75 c. 2.25 d. 1.45

Chapter 03 - Describing Bivariate Data e. unknown ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 2/4/2019 3:33 AM 21. A perfect straight line sloping downward would produce a correlation coefficient equal to: a. +1 b. –1 c. +2 d. –2 e. 0 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 2/4/2019 3:33 AM 22. If all the points in a scatterplot lie on the least-squares regression line, then the correlation coefficient r must

be: a. 1.0 b. –1.0 c. either 1.0 or –1.0 d. 100 e. 10 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 3/29/2019 4:17 AM 23. A manager of a supermarket wishes to show the relationship between the number of customers who come to

the store on weekends, and the total volume of sales (in dollars) during the same weekend. Which of the following graphs would likely be most useful if the manager has a sample of 52 weekends worth of data? a. bar chart b. pie chart c. box and whisker plot d. scatterplot

Chapter 03 - Describing Bivariate Data e. histogram ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 2/4/2019 3:33 AM 24. Given that a. 0.75

= 100, = 64,

= 60, and n = 8, the slope of the best-fitting regression line is:

b. 0.64 c. 0.60 d. 7.5 e. 6.4 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 2/4/2019 3:33 AM 25. The best-fitting regression line can be used to: a. find the actual value of y for a given value of x b. estimate or predict the value of y for a given value of x c. calculate the correlation coefficient d. all of these e. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 2/4/2019 3:33 AM 26. Which value of the correlation coefficient r indicates a stronger correlation than 0.72? a. 0.65 b. –0.75 c. 0.60 d. –0.70 e. 0.55 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice

Chapter 03 - Describing Bivariate Data HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 2/4/2019 3:33 AM 27. A scatterplot can be used to determine the relationship between: a. two qualitative variables b. two quantitative variables c. one qualitative variable and one quantitative variable d. all of these e. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 2/4/2019 3:33 AM 28. In constructing a scatterplot, it would not be appropriate to: a. label the x-axis b. label the y-axis c. label the graph using titles d. connect the data points on the graphs with straight lines e. draw the best-fitting line on the graph ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 3/29/2019 4:20 AM 29. A councilman was interested in determining whether people between the ages of 18 and 30 years of age will

react to a piece of legislation differently than people over 30 years of age. The legislator polled a sample of 150 people from his district. The resulting data is shown in the table below:

Age 18 – 30 years old Over 30 years old

Reaction Favor Oppose 25 40 45 20

No Opinion 15 5

Construct a side-by-side bar chart. Construct a pie chart for the 18 - 30 age group.

Chapter 03 - Describing Bivariate Data

Construct a pie chart for the Over 30 age group. Which of the two types of presentations is more easily understood?

ANSWER:

;

Chapter 03 - Describing Bivariate Data

Pie chart POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 4/1/2019 3:32 AM 30. Male and female respondents to a questionnaire about gender differences are categorized into three groups

according to their answers as shown below: Gender Men Women

Group 1 52 17

Group 2 36 40

Group 3 62 43

Create a side-by-side bar chart to describe these data. Create two pie charts (one for men and one for women) to describe these data. Men: Women: Which of the charts created above best depicts the difference or similarity of the responses of men and women. ANSWER:

;

Chapter 03 - Describing Bivariate Data

;

Pie charts POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 4/1/2019 4:25 AM 31. A law school administrator was interested in whether a student's score on the entrance exam can be used to

predict a student's grade point average (GPA) after one year of law school. The administrator took a random sample of 15 students and computed the following summary information, where x = entrance exam score and y = GPA after one year:

and

Find the correlation between the entrance exam score and the grade point average after one year of law school. Round your answer to three decimal places.

Chapter 03 - Describing Bivariate Data

Interpret the correlation coefficient that you found indicating the direction of the relationship.

Find the best-fitting line relating grade point average after one year of law school and score on the entrance exam. Round the numerical values to four decimal places. y= If a student scored 91 on the entrance exam, what would you predict the student's grade point average to be after one year of law school? Round your answer to three decimal places.

ANSWER:

0.934; There is a positive relationship; -1.6575 + 0.0568x; 3.511

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 3/29/2019 5:25 AM 32. When the price of gasoline gets high, consumers become very concerned about the gas mileage obtained by

their cars. One consumer was interested in the relationship between car engine size (number of cylinders) and gas mileage (miles/gallon). The consumer took a random sample of 7 cars and recorded the following information:

and

Would you expect the correlation between engine size and gas mileage to be positive or negative?

Find the correlation between engine size and gas mileage. Round your answer to three decimal places.

Find the best-fitting line relating car engine size and gas mileage. Round the numerical values to four decimal places. y= What would you predict the gas mileage to be for a car with 6-cylinder engine size? Round your answer to three decimal places.

Chapter 03 - Describing Bivariate Data

mpg ANSWER:

Negative; -0.731; 34.405 - 2.5844x; 18.899

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 3/29/2019 5:26 AM 33. The manager of a movie rental store was interested in examining the relationship between the weekly take-

home pay for a family and the amount that a family spends weekly on recreational activities. The following output was generated using Minitab: Covariances

Let x = weekly take-home pay, and y = amount spent weekly on recreational activities. a. Identify the covariance between x and y.

b. Identify the variance of weekly take-home pay.

c. Identify the variance of amount spent weekly on recreational activities.

d. Calculate the correlation between weekly take-home pay and amount spent weekly on recreational activities. Round your answer to three decimal places.

e. Interpret the correlation coefficient found in part (d) indicating the direction of the relationship.

ANSWER:

2419.64; 4413.84; 1364.29; 0.986; There is a positive relationship

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic

Chapter 03 - Describing Bivariate Data DATE CREATED: DATE MODIFIED:

2/4/2019 3:33 AM 3/29/2019 5:25 AM

34. A soft drink distributor was interested in examining the relationship between the number of ads (x) for his

product during prime time on a local television station and the number of sales per week (y) in thousands of cases. He compiled the figures for 20 weeks and computed the following summary information:

and

Find the correlation coefficient for the number of ads during prime time and weekly sales. Round your answer to three decimal places.

Find the best-fitting line relating the number of ads during prime time and weekly sales. Round the numerical values to four decimal places. y= If the soft drink distributor ran 21 TV ads per week for his product, what would you predict his sales to be? Round your answer to four decimal places.

ANSWER:

thousand cases 0.908; 0.1256 + 1.8966x; 39.9542

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 3/29/2019 5:33 AM 35. The number of household members, x and the amount spent on groceries per week, y (rounded to the nearest

dollar) are measured for eight households in the Big Rapids area. The data are shown below:

Create a raw scatterplot of these eight data points (no regression line or equation). Find the best-fitting regression line for these data. Round the numerical values to three decimal places. y=

Chapter 03 - Describing Bivariate Data

Plot the points and the best-fitting line on the same graph. What would you estimate a household of seven to spend on groceries per week? Round your answer to two decimal places.

Should you use the fitted line to estimate this amount?

Why or why not?

ANSWER:

;

0.1681 + 25.546x;

;

178.99; No; It is risky to try to estimate the value of y for a value of x outside the experimental region - that is, the range of x values for which you have collected data. POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:33 AM DATE MODIFIED: 3/29/2019 5:37 AM

Chapter 03 - Describing Bivariate Data 36. The researchers collected data about full-time year-round workers 25 to 34 years old. They recorded gender,

education level, and median annual earning of each respondent. The resulted data are presented in the table:

Less than high school completion High school completion Some college, no degree Bachelor’s degree

Male $28,560 $34,750 $37,980 $56,960

Female $21,900 $28,000 $29,980 $44,990

Create a side-by-side bar chart to describe the data. Do males earn more than females? a. Yes b. No ANSWER: Yes POINTS: 1 QUESTION TYPE: Yes / No HAS VARIABLES: False DATE CREATED: 2/5/2019 7:12 AM DATE MODIFIED: 2/5/2019 10:32 AM 37. The researcher wanted to study whether the level of happiness of teenagers aged 13 to 16 years depends on

the number of siblings that they have. A survey of 423 teenagers aged 13 to 16 years was conducted and their responses to the question "How happy are you?" were recorded. The responses are shown in the following table:

Siblings 0-1 Siblings 2-3 Siblings 4-5 Siblings >5

Not too happy 36 60 35 11

Pretty happy 70 96 63 9

Very happy 23 12 5 3

Create side-by-side pie charts to determine the possible conclusion. a. In all categories, most teenagers responded that they are not too happy. b. Most teenagers who have 2 or 3 siblings do not consider themselves happy. c. The smallest percentage of responses "Very happy" is among those who have more than 5 siblings. d. Most teenagers who consider themselves very happy have no more than 1 sibling. e. Teenagers who have no more than 1 sibling more often than teenagers who have 4 or 5 siblings

answered that they are pretty happy. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/5/2019 9:13 AM DATE MODIFIED: 2/5/2019 10:33 AM 38. The National Center for Education Statistics (NCES) collects and analyzes data related to education in the

Chapter 03 - Describing Bivariate Data

USA. The table represents the data collected from a sample of 118,430 principals in public and private elementary and secondary schools whose academic degree was recorded.

Public Private

Bachelor’s or less

Master’s

1,320 9,120

55,250 14,030

Education specialist 26,270 2,800

Doctor’s or first professional 7,630 2,010

Create side-by-side pie charts to describe the data. Where do principals most often have a master’s degree? a. Principals most often have a master’s degree in public schools. b. Principals most often have a master’s degree in private schools. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/5/2019 9:44 AM DATE MODIFIED: 2/5/2019 10:34 AM 39. Respondents of three different age groups took part in the survey about technology use. They were

categorized into three groups depending on whether they have a basic cell phone, a smartphone, or they do not have a cell phone at all.

Cell phone, smartphone Cell phone, not smartphone No cell phone

30-49 2,583 326 35

50-64 1,625 503 75

65+ 632 580 304

Create side-by-side pie charts to describe the data. Are basic cell phones the most common among people over 65? a. Yes b. No ANSWER: Yes POINTS: 1 QUESTION TYPE: Yes / No HAS VARIABLES: False DATE CREATED: 2/5/2019 9:58 AM DATE MODIFIED: 2/6/2019 3:40 AM 40. The owners of an online clothing store collected customer data to design a new clothing collection. They

were interested in eye color and gender of customers. The data are presented in the following table:

Female Male

Blue 256 239

Brown 232 186

Green 185 129

Hazel 177 146

Chapter 03 - Describing Bivariate Data

Create the conditional data distribution to describe the data. Is the proportion of blue-eyed females greater than the proportion of blue-eyed males? a. Yes b. No ANSWER: No POINTS: 1 QUESTION TYPE: Yes / No HAS VARIABLES: False DATE CREATED: 2/5/2019 10:07 AM DATE MODIFIED: 2/5/2019 10:36 AM

Chapter 04 - Probability 1. Probability is the tool that allows the statistician to use sample information to make inferences about or

describe the population from which the sample was drawn. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 2/4/2019 3:45 AM 2. When the population is unknown and only a sample from that population is available, probability is used for

statistical inference to draw reliable conclusions from sample information about the population. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 3/29/2019 3:25 AM 3. The probability of an event A is equal to the sum of the probabilities of the simple events contained in A. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 2/4/2019 3:45 AM 4. An experiment consists of tossing 4 unbiased coins simultaneously. The number of simple events in this

experiment is 16. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 2/4/2019 3:45 AM 5. Combinations are distinguishable ordered arrangements of items all of which have been drawn from a given

Chapter 04 - Probability

group of items. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 2/4/2019 3:45 AM 6. An experiment is any activity that results in one and only one of several clearly defined possible outcomes

but that does not allow us to tell in advance which of these will prevail in any particular instance. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 2/4/2019 3:45 AM 7. An event is a collection of one or more simple events of an experiment. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 2/4/2019 3:45 AM 8. A tree diagram shows only mutually exclusive events. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 3/29/2019 4:00 AM 9. Different events that have no outcomes in common are mutually exclusive events. a. True b. False

Chapter 04 - Probability ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 2/4/2019 3:45 AM 10. Invariably, Venn diagrams illustrate only the intersection of two events. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 3/29/2019 4:08 AM 11. Simple events of an experiment that take on values between 0 and 1 are inclusive. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 3/29/2019 4:19 AM 12. There is no difference between simple events and events. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 3/29/2019 4:22 AM 13. If an investor was interested in assessing the probability that a new supermarket will be successful in a New

York market area, he would most likely use the relative frequency definition of probability as the method for assessing the probability of success. a. True b. False ANSWER: POINTS:

True 1

Chapter 04 - Probability QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 2/4/2019 3:45 AM 14. When a patient who is complaining of several specific symptoms arrives at a doctor's office, the doctor who

makes the diagnosis says that she is 90% certain that the patient has the flu, it is likely that she is basing her assessment on relative frequency approach of assigning probabilities. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 2/4/2019 3:45 AM 15. Which of the following statements is true? a. An experiment is the process by which an observation or measurement is obtained. b. An event that cannot be decomposed is called a simple event. c. An event is the collection of one or more simple events. d. An experiment is the process by which an observation or measurement is obtained and an event is the

collection of one or more simple events. e. All of these statements are true. ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 3/29/2019 4:32 AM 16. The set of all simple events of an experiment is called: a. a compound event b. a sample space c. a population d. a random sample e. all of these ANSWER:

POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 2/4/2019 3:45 AM

Chapter 04 - Probability 17. A graphical method of displaying the sample space for an experiment, where each successive level of

branching on the tree corresponds to a step required to generate the final outcome, is: a. a tree diagram b. a box plot c. a histogram d. a scatterplot e. a barplot ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 4/1/2019 12:56 AM 18. Which of the following correctly describes experiments? a. They are two random events, A and B, such that the probability of one event is not affected by the

occurrence of the other event; therefore, P(A) = P(A|B). b. They are different events that have no outcomes in common. c. They are activities that result in one and only one of several clearly defined possible outcomes and that do not allow us to tell in advance which of these will prevail in any particular instance. d. All of the above. e. None of these. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 2/4/2019 3:45 AM 19. The sample space for an experiment can be represented by: a. a joint probability table b. the additive rule of probability c. the multiplicative rule of probability d. a tree diagram e. None of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 2/4/2019 3:45 AM

Chapter 04 - Probability 20. Any subset of the sample space is called: a. an event b. an experiment c. mutually exclusive events d. independent events e. None of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 2/4/2019 3:45 AM 21. Which of the following statements is correct? a. The experiment of tossing a single coin once contains 1 simple event. b. The experiment of rolling a single die once contains 6 simple events. c. The experiment of spinning the Monte Carlo roulette wheel once contains 27 simple events. d. The experiment of drawing a single card once from a standard deck contains 4 events. e. The experiment of tossing a coin twice contains 2 simple events. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 2/4/2019 3:45 AM 22. Which of the following statements is false? a. The probability of getting the king of diamonds when randomly drawing a card from a well-shuffled

deck is 1/52. b. The probability of getting a black card when randomly drawing a card from a well-shuffled deck is 1/2. c. The probability of getting a 10 when randomly drawing a card from a well-shuffled deck is 4/52. d. The probability of getting two heads when tossing a fair coin twice is 1/4. e. The probability of getting the king of spades when randomly drawing a card from a well-shuffled deck is 4/52. ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 4/16/2019 5:02 AM 23. An experiment consists of tossing 3 unbiased coins simultaneously. The number of simple events in this

Chapter 04 - Probability

experiment is: a. 3 b. 6 c. 8 d. 9 e. 27 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 2/4/2019 3:45 AM 24. An experiment consists of three stages. There are three ways to accomplish the first stage, four ways to

accomplish the second stage, and five to accomplish the third stage. Then, the number of ways to accomplish the experiment is: a. 60 b. 12 c. 15 d. 20 e. 4 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 2/4/2019 3:45 AM 25. The possible number of combinations of 3-digit elements out of 8 distinct items equals: a. 28 b. 56 c. 112 d. 224 e. 24 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 4/1/2019 1:09 AM 26. An event is:

Chapter 04 - Probability a. an experiment that is not controlled by the decision maker b. the outcome observed on a single repetition of an experiment c. a collection of one or more simple events d. a collection of two or more simple events e. None of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 4/1/2019 1:15 AM 27. When Cynthia goes to a grocery store, there are three simple events: buy nothing, buy a small amount, or

buy a large amount. In this situation, if Cynthia buys a small amount, she cannot also buy a large amount or buy nothing. Thus the three events are: a. mutually exclusive b. not mutually exclusive c. dependent events d. independent events e. none of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 4/1/2019 1:19 AM 28. Which of the following statements is false? a. The set of all simple events of an experiment is called the sample space. b. An event that can be decomposed into two is called a simple event. c. The sum of the probabilities for all simple events in the sample space equals 1. d. The probability of an event A is equal to the sum of the probabilities of the simple events contained

in A. e. The probability for any event in the sample space is between 0 and 1 inclusive. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 4/1/2019 1:20 AM 29. A manufacturing firm producing odd-sized decorative windows buys the window frames from either

Chapter 04 - Probability

supplier S1 or supplier S2. The firm sells the finished window to either customer C1 or customer C2. a. Describe the sample space; that is, list all possible supplier-customer combinations, which a given finished window might represent.

b. If each supplier-customer combination in part (a) is equally likely, what is the probability a randomly chosen finished window is sold to customer C1?

ANSWER:

a. S = {(C1, S1), (C1, S2), (C2, S1), (C2, S2)}; b. 0.50

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 4/1/2019 1:22 AM 30. A political scientist asked a group of people how they felt about two political policy statements. Each person

was to respond A (agree), N (neutral), or D (disagree) to each policy statement. a. Describe the sample space; that is, list all possible response combinations to the two statements.

b. Assuming each response combination in part (a) is equally likely, what is the probability the person being interviewed agrees with at least one of the two policy statements?

c. Assuming each response combination in part (a) is equally likely, what is the probability the person being interviewed agrees with exactly one of the two political policy statements?

d.Assuming each response combination in part (a) is equally likely, what is the probability the person being interviewed agrees with the two political policy statements?

ANSWER:

a. {AA, AN, AD, NA, NN, ND, DA, DN, DD};

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic

Chapter 04 - Probability DATE CREATED: DATE MODIFIED:

2/4/2019 3:45 AM 2/4/2019 3:45 AM

31. Three randomly chosen fourteen-year-old junior high students who had not yet taken driver's education

classes were given the written part of the Michigan Driver's Exam. Each student was graded as passing (P) or failing (F) the written exam. a.Describe the sample space; that is, list all possible combinations of the three students' grades.

b.Assuming each combination in part (a) is equally likely, what is the probability all three students fail?

c.Assuming each combination in part (a) is equally likely, what is the probability at least one student passes the written test?

d.Assuming each combination in part (a) is equally likely, and if you knew at least one student passed the test, what is the probability all three students passed the test?

ANSWER:

a. {PPP, PPF, PFP, FPP, PFF, FPF, FFP, FFF};

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 2/4/2019 3:45 AM 32. Margaret selected two M&M candies one by one at random from a bowl containing three M&Ms, one red,

one yellow, and one orange. a. Describe the sample space.

b. Suppose Margaret draws the first M&M red color, likes it, and eats it before drawing the next two M&M candies one by one. What is the sample space in this case?

ANSWER:

a. {RY, RO, YR, YO, OR, OY}; b. {YO, OY}

POINTS:

Chapter 04 - Probability QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 4/2/2019 3:41 AM 33. A salesperson either makes a sale (S) or does not make a sale (N) with each of two potential customers. The

simple events and their probabilities are given below.

a. What is the probability that no sales are made?

b. What is the probability that at least one sale is made?

c. What is the probability that exactly one sale is made?

d. What is the probability that exactly two sales were made?

ANSWER: a. 0.65; b. 0.35; c. 0.27; d. 0.08 POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 2/4/2019 3:45 AM 34. Five applicants apply for two jobs. Applicants A and B are male; applicants C, D, and E are female. The

personnel officer selects two applicants at random to fill the two jobs. List all possible combinations of two applicants for two different jobs. a. List all possible combinations of two applicants for two identical jobs.

Chapter 04 - Probability

b. If the two jobs are different, and E1 denote the collection of outcomes where the successful job applicants

include at least one male, what is P(E1)?

c. If the two jobs are identical, and E2 denote the collection of outcomes where the successful job applicants

include at least one male, what is P(E2)?

d. If the two jobs are different, and E3 denote the collection of outcomes where the successful job applicants

include exactly one male, what is P(E3)?

e. If the two jobs are identical, and E4 denote the collection of outcomes where the successful job applicants

include exactly one male, what is P(E4)?

f. If the two jobs are different, and, E5 denote the collection of outcomes where the successful job applicants

include at least one female, what is P(E5)?

g. If the two jobs are identical, and E6 denote the collection of outcomes where the successful job applicants

include at least one female, what is P(E6)?

h. If the two jobs are different, and E7 denote the collection of outcomes where the successful job applicants

include exactly one female, what is P(E7)?

i. If the two jobs are identical, and E8 denote the collection of outcomes where the successful job applicants

include exactly one female, what is P(E8)?

ANSWER:

{AB, AC, AD, AE, BA, BC, BD, BE, CA, CB, CD, CE, DA, DB, DC, DE, EA, EB, EC, ED}; a. {AB, AC, AD, AE, BC, BD, BE, CD, CE, DE} ; b. 0.7; c. 0.7; d. 0.6; e. 0.6; f. 0.9; g. 0.9; h. 0.6; i. 0.6

Chapter 04 - Probability POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 2/4/2019 3:45 AM 35. A sample space S consists of five simple events with these probabilities:

a. Find the probability for simple event E4.

b. Find the probability of occurrence of these three simple events: A: E1, E3, E4.

c. B: E2, E4.

d. List the simple events that are either in event A or event B or both.

e. List the simple events that are in both event A and event B. ANSWER:

a. 0.10; b. 0.75; c. 0.30; d. {E1, E2, E3, E4}; e. {E4}

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 4/1/2019 3:24 AM 36. a. A food company conducts an experiment to compare its brand of coffee with that of two competitors. A

single person is hired to taste each of three brands of coffee, which are unmarked except for identifying symbols, A, B, and C. Define the experiment.

b. List the simple events in the sample space S.

Chapter 04 - Probability

c. If the taster has no ability to distinguish difference in taste among coffees, what is the probability that the taster will rank coffee type C as the most desirable?

d. As the least desirable?

ANSWER:

a. Experiment: A taster tastes and marks three varieties of coffee, A, B, and C, according to preference.; b. Simple events in S are in triplet form, where 1 is assigned to the most desirable, 2 to the next most desirable, and 3 to the least desirable.;

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 4/1/2019 3:27 AM 37. A graduate student has decided she needs a day at the beach. She will need a swimsuit, a pair of sunglasses

and a beach towel for the occasion. If she has 2 swimsuits, 3 pairs of sunglasses and 5 beach towels, how many different choices does she have?

ANSWER:

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 2/4/2019 3:45 AM 38. A professor has received a grant to travel to an archaeological dig site. The grant includes funds for three

graduate students to accompany the professor. If there are six graduate students available to the professor and all the funds are to be used (i.e., three students will go), how many choices does the professor have?

ANSWER:

POINTS: QUESTION TYPE: HAS VARIABLES:

1 Subjective Short Answer False

Chapter 04 - Probability STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 2/4/2019 3:45 AM 39. An interior decorator must furnish two offices. Each office must have a desk, a chair, a file cabinet and 2

bookcases. At the local office furniture store there are 6 models of desks, 8 models of chairs, 4 models of file cabinets and 10 models of bookcases, all of which are compatible. (Any desk can be matched with any chair, etc.) How many choices does the decorator have if he wants to select two desks, two chairs, two file cabinets and four bookcases if he doesn't want to select more than one of any model?

ANSWER:

529200

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 4/1/2019 3:29 AM 40. A businessman in Chicago is preparing an itinerary to visit five major cities. Each city will be visited once

and only once. The distance traveled, and hence the cost of the trip, will depend on the order in which he plans his route. How many different itineraries (and trip costs) are possible?

ANSWER:

120

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 4/1/2019 3:31 AM 41. An Italian restaurant in Grand Rapids, Michigan, offers a special summer menu in which, at a fixed dinner

cost, you can choose from one of two salads, one of three entrees, and one of four deserts. How many different dinners are available?

ANSWER:

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 4/1/2019 3:33 AM

Chapter 04 - Probability 42. Heidi prepares for an exam by studying a list of 15 problems. She can solve nine of them. For the exam, the

instructor selects seven questions at random from the list of fifteen. What is the probability that Heidi can solve all seven problems on the exam?

ANSWER:

0.0056

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 2/4/2019 3:45 AM 43. How many different combinations of 5 students can be drawn from a class of 25 students?

ANSWER:

53130

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 2/4/2019 3:45 AM 44. How many permutations of 3 colors can be drawn from a group of 20 colors?

ANSWER:

6840

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:45 AM DATE MODIFIED: 2/4/2019 3:45 AM 45. The intersection of events A and B is the event that A or B or both occur. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM

Chapter 04 - Probability 46. The complement of an event A, denoted by

, consists of all the simple events in the sample space S that

are not in A. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 47. The conditional probability of event B, given that event A has occurred is defined by:

. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 48. Two events A and B are said to be independent if and only if P(A / B) = P(B) or P(B / A) = P(A). a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 49. If P(A) > 0, P(B) > 0, and P(A B) = 0, then the events A and B are independent. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 50. If P(A) = 0.4, P(B) = 0.5, and P(A

B) = 0.20, then the events A and B are mutually exclusive.

Chapter 04 - Probability a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 51. If P(A) > 0 and P(B) > 0, then when A and B are mutually exclusive events, they are also dependent events. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 52. If P(A) = 0.3, P(A B) = 0.7, and P(A a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM

B) = 0.2, then P(B) = 0.2.

53. If P(A) = 0.4, P(B) = 0.5, and P(A B) = 0.7, then P(A a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM

B) = 0.2.

54. If P(A) = 0.60, P(B) = 0.40, and P(B / A) = 0.60, then P(A / B) = 0.24. a. True b. False ANSWER: False POINTS: 1

Chapter 04 - Probability QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 55. If A and B are independent events with P(A) = 0.30 and P(B) = 0.50, then P(A/B) is 0.15. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 56. The probability that event A will not occur is 1-

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 57. If P(A / B) = P(A), then events A and B are said to be independent. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 58. Conditional probability is the probability that an event will occur, with no other events taken into

consideration. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM

Chapter 04 - Probability DATE MODIFIED: 2/4/2019 3:46 AM 59. If A and B are two independent events with P(A) = 0.25 and P(B) = 0.45, then P(A a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM

B) = 0.70.

60. If P(A) = 0, P(B) = 0.4, and P(A B) = 0, then events A and B are independent. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 61. Two events A and B are said to be independent if P(A a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM

B) = P(A) + P(B).

62. Two events A and B are said to mutually exclusive if P(A a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM

B) = 0.

63. Suppose A and B are mutually exclusive events where P(A) = 0.1 and P(B) = 0.7, then P(A a. True

B) = 0.8.

Chapter 04 - Probability b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 64. Suppose A and B are mutually exclusive events where P(A) = 0.2 and P(B) = 0.3. Then P(A a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 65. Suppose A and B are events, where P(A) = 0.4, P(B) = 0.5, and P(A a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 4/18/2019 3:21 AM

B) = 0.5.

B) = 0.2. Then P(B / A) = 0.4.

66. All the outcomes contained in one or the other of two events (or possibly in both) constitute the intersection

of two events. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 4/18/2019 4:30 AM 67. The addition rule of probability is used to compute the probability for an intersection of two or more events:

namely, given two events A and B, a. True b. False ANSWER:

False

and also

Chapter 04 - Probability POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 4/18/2019 3:24 AM 68. The addition law of probability theory is used to compute the probability for the occurrence of a union of

two or more events; namely, given two events A and B, a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 69. Which one of the following is always true for two events, A and B? a. If A and B are independent, they are also mutually exclusive. b. If A and B are dependent, they are also mutually exclusive. c. If P(A / B) = P(A B), A and B are independent. d. If A and B are mutually exclusive, then A e. All of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 70.

is: a. the union of two events b. the intersection of two events c. the complement of an event d. the addition rule of probability

e. none of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 4/18/2019 3:30 AM

B can never occur on the same trial of an experiment.

Chapter 04 - Probability 71. The probability of an event and the probability of its complement always sum to: a. –1 b. 0 c. 1 d. any value between 0 and 1 e. 0.5 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 72. Suppose P(A) = 0.4, P(B) = 0.3, and P(A

B) = 0. Which one of the following statements correctly defines the relationship between events A and B? a. Events A and B are independent, but not mutually exclusive. b. Events A and B are mutually exclusive, but not independent. c. Events A and B are neither mutually exclusive nor independent. d. Events A and B are both mutually exclusive and independent. e. None of these. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 73. If events A and B are mutually exclusive, then the probability of both events occurring simultaneously is

equal to: a. –1 b. 0 c. 1 d. any value between 0 and 1 e. 0.5 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 74. If P(A/B) = P(A), or P(B/A) = P(B), then events A and B are said to be:

Chapter 04 - Probability a. mutually exclusive b. disjoint c. independent d. dependent e. B contains A. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 75. If P(A) = 0.80, P(B) = 0.70 and P(A a. 0.60

B) = 0.90, then P(A B) is:

b. 0.56 c. 0.72 d. 0.63 e. 0.5 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 76. If P(A) = 0.30, P(B) = 0.40 and P(A a. 0.12

B) = 0.20, then P(A / B) is:

b. 0.08 c. 0.67 d. 0.50 e. 0.3 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 77. If P(A) = 0.40, P(B) = 0.30 and P(A a. dependent events b. independent events c. mutually exclusive events

B) = 0.12, then A and B are:

Chapter 04 - Probability d. disjoint events e. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 78. If P(A) = 0.42 and P(B) = 0.38, then P(A a. 0.80

B) is:

b. 0.58 c. 0.04 d. 0.42 e. Cannot be determined from the given information. ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 79. All the outcomes (simple events) contained in one or the other of two random events, or possibly in both,

make up: a. the events of an experiment b. the intersection of two events c. the probability space of an experiment d. the union of two events e. the complement of the other event ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 80. Which of the following clearly describes the general multiplicative rule of probability? a. It is a rule of probability theory that is used to compute the probability for the occurrence of a union

of two or more events: for any two events, A and B, . b. It is a rule of probability theory that is used to compute the probability for the occurrence of a union of two or more events: for any two events A and B, . c. It is a rule of probability theory that is used to compute the probability for an intersection of two or more events: for any two events, A and B,

Chapter 04 - Probability d. It is a rule of probability theory that is used to compute the probability for an intersection of two or

more events: for any two events A and B, e. All of these. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 81. Which of the following best describes the concept of conditional probability? a. It is a measure of the likelihood that a particular event will occur, regardless of whether another event

occurs. b. It is a measure of the likelihood that a particular event will occur, given the fact that another event has already occurred or is certain to occur. c. It is a measure of the likelihood of the simultaneous occurrence of two or more events. d. It is a direct way for defining the sample space of an experiment. e. It is a measure of the likelihood that a particular event will not occur. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 4/18/2019 4:41 AM 82. In the case of independent events A, B, and C, a. b. c. d. e. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 83. Two events A and B are said to be dependent if and only if: a. P(A) = P(B) b. P(A) increases along with P(B) c. P(A) increases as P(B) decreases

equals:

Chapter 04 - Probability d. Event A is affected or changed by the occurrence of event B, or vice versa e. P(A) < P(B) ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 4/18/2019 4:59 AM 84. A group of forty people at a health club were classified according to their gender and smoking habits, as

shown below:

Round your answers to four decimal places, if necessary. a. One person is selected at random from that group of forty people. What is the probability the person smokes?

b. What is the probability the person is female but does not smoke?

c. What is the probability the person is male?

e. What is the probability the person is female?

f. What is the probability the person is male and smokes?

g. If the person was male, what is the probability he smokes?

Chapter 04 - Probability

h. If the person was female, what is the probability she does not smoke?

ANSWER:

a. 0.2; b. 0.2; c. 0.65; e. 0.35; f. 0.05; g. 0.0769; h. 0.5714

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 4/3/2019 7:49 AM 85. One hundred shoppers at a local shopping mall were categorized by age and gender as shown in the

frequency distribution below:

a. One shopper is selected at random form that group of 100 shoppers. What is the probability the randomly selected shopper is under 25 years of age?

b. What is the probability the randomly selected shopper is male?

c. What is the probability the randomly selected shopper is male and under 25 years of age?

d. If the randomly selected shopper is male, what is the probability he is under 25 years of age?

e. If the randomly selected shopper is under 25 years of age, what is the probability the shopper is male?

f. What is the probability the randomly selected shopper is female or over 40 years of age?

Chapter 04 - Probability

g. If the randomly selected shopper is female, what is the probability that she is 25 to 40 years old?

h. Are gender of the shopper and age mutually exclusive events?

i. Explain.

j. Are gender of the shopper and age independent events? Explain.

k. Explain.

ANSWER:

a. 0.39; b. 0.40; c. 0.15; d. 0.375; e. 0.3846; f. 0.72; g. 0.30; h. No; i. Gender of the shopper and age are not mutually exclusive events because they can occur at one time, for ex. male and over 40 years; j. No; k. Gender of the shopper and age are not independent events, because probability that gender of the shopper is male/female affects on the probability of the age, and vice versa

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 4/18/2019 6:17 AM 86. A psychologist tests seventh grade students on basic word association skills and number pattern recognition

skills. Let W be the event a student does well on the word association test. Let N be the event a student does well on the number pattern recognition test. For a randomly selected student, assume that the following probabilities are given:

a. What is the probability the randomly selected student does well on the word association test?

Chapter 04 - Probability

b. What is the probability the randomly selected student does well on the number pattern recognition test?

c. What is the probability the randomly selected student does well on at least one of the tests?

d. If the randomly selected student does well on the word association test, what is the probability he or she will also do well on the number pattern recognition test?

e. If the randomly selected student does well on the number pattern recognition test, what is the probability he or she will also do well on the word association test?

f. Are the events W and N mutually exclusive? Justify your answer.

g. Explain.

h. Are the events W and N independent?

i. Explain.

ANSWER:

a. 0.40; b. 0.35; c. 0.50; d. 0.625; e. 0.7143; f. No; g. They are not mutually exclusive because P( W and N) = 0.25; h. No; i. They are not independent. For example, P(W / N ) = 0.7143 is not = P(W) = 0.40

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 4/18/2019 5:52 AM 87. Studies have shown a particular television commercial is understood by 25% of first grade students and 80%

Chapter 04 - Probability

of fourth grade students. If a television advertising agency randomly selects one first grader and one fourth grader, what is the probability neither child would understand the commercial, assuming the children's reactions are independent?

ANSWER:

0.15

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 88. A researcher studied the relationship between the salary of a working woman with school-aged children and

the number of children she had. The results are shown in the following probability table:

a. What is the probability that a working woman has 2 or fewer children?

b. What is the probability that a working woman has a low salary?

c. What is the probability that a working woman has 2 or fewer children and has a low salary?

d. What is the probability that a working woman has 2 or fewer children or has a low salary?

e. If a working woman has 2 or fewer children, what is the probability that she has a low salary?

Chapter 04 - Probability

f. If a working woman has a low salary, what is the probability that she has 2 or fewer children?

g. Are the salary of a working woman with school-aged children and the number of children she had independent events?

ANSWER:

a. 0.63; b. 0.55; c. 0.30; d. 0.88; e. 0.4762; f. 0.5455; g. No

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 4/19/2019 1:18 AM 89. Research studies suggest that the likelihood a drug offender will be convicted of a drug offense within two

years after treatment for drug abuse may depend on the person's educational level. The proportion of the total number of cases that fall into four education/conviction categories are shown in the table below:

Suppose a single offender is selected from the treatment program. Here are two events of interest: A: The offender has 10 or more years of education B: The offender is convicted within two years after completion of treatment a. Find P(A)

b. Find P(B)

c. Find

Chapter 04 - Probability

d. Find

e. Find

f. Find

g. Find

h. Find A given that B has occurred

i. Find B given that A has occurred

j. Are events A and B independent?

ANSWER:

a. 0.40; b. 0.35; c. 0.10; d. 0.65; e. 0.60; f. 0.35; g. 0.90; h. 0.2857; i. 0.25; j. No

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 90. A missile designed to destroy enemy satellites has a 0.80 chance of destroying its target. If the government

tests three missiles by firing them at a target, what is the probability all three fail to destroy the target? (Assume the missiles perform independently.)

ANSWER:

0.008

Chapter 04 - Probability POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 91. Let A be the event that a randomly selected person watches the Tonight Show with Jay Leno and B be the

event that a randomly selected person watches the Late Show with David Letterman. Since most homes have VCRs, it is possible to time-shift a program to a more convenient hour and thus watch both programs. Suppose the following probabilities are given:

a. What is the probability that a randomly selected person watches both shows?

b. What is the probability that a randomly selected person watches only Jay Leno?

c. What is the probability that a randomly selected person watches only David Letterman?

d. What is the probability that a randomly selected person watches Jay Leno?

e. What is the probability that a randomly selected person watches David Letterman?

f. If we know a person watches Jay Leno, what is the probability he or she also watches David Letterman?

g. If we know a person watches David Letterman, what is the probability he or she also watches Jay Leno?

Chapter 04 - Probability

h. Are the events A and B independent?

ANSWER:

a. 0.20; b. 0.40; c. 0.10; d. 0.60; e. 0.30; f. 0.333; g. 0.667; h. No

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 92. An election is being held to fill two "at large" city council seats. Two Republicans and three Democrats are

running for office. Assume the candidates are equally likely to be elected, and independent of each other. a. What are the possible outcomes of the election?

b. What is the probability both seats are filled by Republicans?

c. What is the probability one Republican and one Democrat are elected to the two city council seats?

ANSWER:

a. RR, RD, DR, DD; b. 0.25; c. 0.50

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 4/2/2019 12:09 AM 93. Four different kinds of radar systems designed to detect or monitor the airspace around a major airport for

high flying objects, low flying objects, runway traffic, and wind shear operate independently. If each system has probability 0.90 of functioning correctly, find the probability at least one radar system will fail.

ANSWER:

0.3439

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic

Chapter 04 - Probability DATE CREATED: DATE MODIFIED:

2/4/2019 3:46 AM 4/2/2019 12:14 AM

94. A box contains one red, three blue and two green marbles. Two marbles are randomly selected without

replacement. Let R = {The selected marble is red.} B = {The selected marble is blue.} G = {The selected marble is green.} C = {Both marbles selected are the same color.} D = {At least one of the marbles is blue.} a. Find P(C).

b. Find P(D).

c. Find

d. Find

e. Find P(D | C).

ANSWER:

a. 0.2667; b. 0.80; c. 0.20; d. 0.8667; e. 0.75

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 95. A federal agency is trying to decide which of two waste management projects to investigate as the source of

air pollution. In the past, projects of the first type were in violation of air quality standards with probability 0.3

Chapter 04 - Probability

on any given day, while projects of the second type were in violation of air quality standards with probability 0.25 on any given day. It is not possible for both projects to pollute the air in one day. Let Ai, i = 1, 2, denote that project of type i was in violation of air quality standards. a. Find the probability of an air pollution problem caused by either the first project or the second project.

b. If the first project is violating air quality standards on a certain day, what is the probability the second project is also violating federal air quality standards on the same day?

ANSWER:

a. 0.55; b. 0.0

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 4/2/2019 12:26 AM 96. A hand soap manufacturer introduced a new liquid, lotion-enriched, antibacterial soap and conducted an

extensive consumer survey to help judge the success of the new product. The survey showed 40% of the consumers had seen an advertisement for the new soap, 20% had tried the new soap, and 15% had both seen an advertisement and tried the new soap. a. What is the probability a randomly selected consumer had either seen an advertisement or tried the new soap?

b. If a randomly chosen consumer has seen an advertisement for the new soap, what is the probability he or she has tried the product?

ANSWER:

a. 0.45; b. 0.375

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 4/19/2019 4:44 AM 97. A laboratory test for a disease affecting 5% of the population is either positive, indicating the disease is

present, or negative, indicating the disease is not present. When people having the disease are tested, 80% of the tests come back positive, and when people who don't have the disease are tested, 15% of the tests come back from the lab marked positive (a false positive result). What is the chance a randomly chosen person's test results would come back positive?

Chapter 04 - Probability

ANSWER:

0.1825

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 98. Applicants for a musical instrument manufacturer are asked to take a manual dexterity test. Past history has

shown that only 25% of the applicants are able to finish the test in the allotted time. Two applicants are selected at random from the applicant pool. a. What is the probability that both applicants finish the test in the allotted time?

b. Justify your answer.

c. What is the probability the first applicant completes the test in the allotted time but the second applicant does not?

d. Justify your answer.

ANSWER:

a. 0.0625; b. Since the applicants are independent of each other, P(Both applicants finish the test in the allotted time) = (0.25)(0.25)= 0.0625; c. 0.1875; d. Since the applicants are independent of each other, P(First applicant completes the test on time but second applicant does not) = (0.25)(0.75) = 0.1875.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 99. Of the delegates at a convention, 60% attended the breakfast forum, 70% attended the dinner speech, and

40% attended both events. a. If a randomly selected delegate is known to have attended the dinner speech, what is the probability he or she also attended the breakfast forum?

Chapter 04 - Probability

b. What is the probability that a randomly selected delegate either attended the breakfast forum, or attended the dinner speech, or attended both?

ANSWER:

a. 0.5714; b. 0.90

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 100. Two types of home smoke detectors, A and B, were tested. If a smoke is present, the probability that it will be identified by smoke detector A is 0.97, by smoke detector B - 0.94, and by both detectors - 0.93. a. If a smoke is present, find the probability that the smoke will be identified by smoke detector A or B or both smoke detectors.

b. Find the probability that the smoke will not be identified. ANSWER:

a. 0.98; b. 0.02

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 4/22/2019 3:08 AM 101. A student has decided to study at a local coffee shop. After some time, she gets hungry. There are two

beverages available: tea and coffee and three bakery items: donuts, muffins and bagels. Define the following events: C = {student gets coffee to drink} T = {student gets tea to drink} D = {student gets a donut to eat} M = {student gets a muffin to eat} B = {student gets a bagel to eat}

Chapter 04 - Probability

a. She decides she wants to get one item to eat and one item to drink. List the elements in the sample space S.

b. If each combination is equally likely, what is the probability the student gets coffee and a bagel?

c. If each combination is equally likely, what is the probability the student gets a muffin and coffee or tea?

d. If each combination is equally likely, what is the probability the student does not get a donut?

ANSWER:

a. {(C,D),(C,M),(C,B),(T,D),(T,M),(T,B)};

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 102. Two hundred single-sport athletes were cross-classified according to gender as follows:

a. An athlete is selected at random. What is the probability that the athlete is a runner?

b. What is the probability that the athlete is a female runner?

c. If the athlete is known to be a runner, what is the probability that the athlete is female?

d. What is the probability that the athlete is male or a swimmer or both?

Chapter 04 - Probability

e. Are the events being a female and being a swimmer mutually exclusive?

f. Are the single-sport type and gender of athletes independent?

ANSWER:

a. 0.55; b. 0.25; c. 0.4545; d. 0.65; e. No; f. No

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 103. At a local pet adoption center for dogs and cats, it is known that if a person adopts a pet, there is a 0.45

probability that it will be a cat and a 0.55 probability that it will be a dog. If a cat is adopted, the probability that it is female is 0.60. If a dog is adopted, the probability that it is female is 0.35. An adopted pet is selected at random and is found to be male. What is the probability that the adopted pet is a dog?

ANSWER:

0.6651

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 104. Suppose that P(A) = 0.6, P(B) = 0.7, and that events A and B are independent.

a. Find

b. Find

c. Find P (A | B).

Chapter 04 - Probability

d. Find P (B | A).

ANSWER:

a. 0.42; b. 0.88; c. 0.6; d. 0.7

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 4/22/2019 4:28 AM 105. Suppose that P(A) = 0.4, P(B) = 0.5, and that events A and B are mutually exclusive.

a. Find

b. Find

ANSWER:

a. 0.0; b. 0.9

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 106. An experiment can result in one or both of events A = Smoker and B = Female, with the joint probabilities

shown in the table below. A person is selected at random.

a. Find the probability that the person is smoker.

b. Find the probability that the person is female.

Chapter 04 - Probability

c. Find the probability that the person is a female smoker.

d. Find the probability that the person is either smoker or female or both.

e. If the person is female, find the probability that she is a smoker.

f. Find the probability that the person is female given that she smokes.

g. Are smoking and gender of the person mutually exclusive events?

h. Are smoking and gender of the person independent events?

ANSWER:

a. 0.55; b. 0.75; c. 0.40; d. 0.90; e. 0.5333; f. 0.7273; g. No; h. No

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 4/2/2019 12:39 AM 107. Lily frequents one of two fast food restaurants, choosing McDonald 25% of the time and Burger King 75%

of the time. Regardless of where she goes, she buys French Fries on 60% of her visits. a. The next time Lily goes into a fast food restaurant, what is the probability that she goes to McDonald and orders French Fries?

b. Are the two events in the previous question independent? Explain.

c. Explain.

Chapter 04 - Probability d. If Lily goes to a fast food restaurant and orders French Fries, what is the probability that she is at Burger King? e. What is the probability that Lily goes to McDonald or orders French Fries or both?

ANSWER:

a. 0.15; b. Yes; c. Since P(F) = 0.60 regardless of whether Lily visits McDonald or Burger King, the two events are independent.; d. 0.75; e. 0.70

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 4/2/2019 1:32 AM 108. An experiment was conducted with three mutually events S1, S2, S3. One and only one event can occur with the corresponding probability P(S1) = 0.5, P(S2) = 0.2 and P(S3) = 0.9. The probabilities that an event A occurs, given S1, S2, S3 has occured are P(A | S1) = 0.2 P(A | S2) = 0.1 P(A | S3) = 0.4 Find the probabilities. P(A) =

P(S1 | A) = P(S2 | A) =

P(S3 | A) = ANSWER: 0.48; 0.208; 0.042; 0.75 POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 4/22/2019 6:30 AM 109. A university in Alabama has 1000 employees. Four hundred of the employees have at least 20 years of

experience (event A), 100 are African American (event B), and 300 with a background in Microsoft Office 2003 (event C). Assume events A, B, and C are independent.

Chapter 04 - Probability

a. What is the probability of finding an employee who meets all three of these criteria?

b. What is the probability of finding an employee who meets at least two of the three criteria?

ANSWER:

a. 0.012; b. 0.166

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:46 AM DATE MODIFIED: 2/4/2019 3:46 AM 110. Bayes' Rule is a formula for revising an initial subjective (prior) probability value on the basis of results

obtained by an empirical investigation and for, thus, obtaining a new (posterior) probability value. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:47 AM DATE MODIFIED: 2/4/2019 3:47 AM 111. Given a set of events

that are mutually exclusive and exhaustive and an event A, the law of total probability states that P(A) can be expressed as P(A) = P(S1)P(A | S1) + P(S2)P(A | S2) + ... + P(Sk)P(A | Sk). a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:47 AM DATE MODIFIED: 4/22/2019 4:57 AM 112. A false positive in screening tests is the event that the test is negative for a given condition, given that the

person has the condition. a. True b. False ANSWER:

False

Chapter 04 - Probability POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:47 AM DATE MODIFIED: 2/4/2019 3:47 AM 113. A false negative in screening tests is the event that the test is positive for a given condition, given that the

person does not have the condition. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 3:47 AM DATE MODIFIED: 2/4/2019 3:47 AM 114. A false negative in screening tests (e.g., Steroid testing of athletes) represents the event that: a. the test is negative for a given condition, given that the person does not have the condition b. the test is positive for a given condition, given that the person does not have the condition c. the test is negative for a given condition, given that the person has the condition d. the test is positive for a given condition, given that the person has the condition ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:47 AM DATE MODIFIED: 2/4/2019 3:47 AM 115. A false positive in screening (e.g., home pregnancy tests) represents the event that: a. the test is negative for a given condition, given that the person does not have the condition b. the test is positive for a given condition, given that the person does not have the condition c. the test is negative for a given condition, given that the person has the condition d. the test is positive for a given condition, given that the person has the condition ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:47 AM DATE MODIFIED: 2/4/2019 3:47 AM 116. Screening tests (e.g., AIDS testing) are evaluated on the probability of a false negative or a false positive,

and both of these are: a. conditional probabilities

Chapter 04 - Probability b. probability of the intersection of two events c. probability of the union of two events d. marginal probabilities e. probability of dependent events ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 3:47 AM DATE MODIFIED: 2/4/2019 3:47 AM 117. A sample is selected from one of two populations, S1 and S2, with probabilities P(S1) = 0.80 and P(S2) =

0.20. If the sample has been selected from S1, the probability of observing an event A is P(A | S1) = 0.15. Similarly, If the sample has been selected from S2, the probability of observing A is P(A | S2) = 0.25. Round your answer to four decimal places, if necessary a. If a sample is randomly selected from one of the two populations, what is the probability that event A occurs?

If a sample is randomly selected and event A is observed, what is the probability that the sample was selected: b. From population S1?

c. From population S2?

ANSWER:

a. 0.17; b. 0.7059; c. 0.2941

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:47 AM DATE MODIFIED: 4/22/2019 4:53 AM 118. Steve takes either a bus or the subway to go to work with probabilities 0.25 and 0.75, respectively.

When he takes the bus, he is late 40% of the days. When he takes the subway, he is late 30% of the days. If Steve is late for work on a particular day, what is the probability that he took the bus?

ANSWER:

0.3077

Chapter 04 - Probability POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:47 AM DATE MODIFIED: 2/4/2019 3:47 AM 119. Medical case histories indicate that different illnesses may produce identical symptom. Suppose a particular

set of symptoms, which we will denote as event H, occurs only when any one of these illnesses: A, B, or C occurs. (For the sake of simplicity, we will assume that illnesses A, B, and C are mutually exclusive.) Studies show these probabilities of getting the three illnesses:

The probabilities of developing the symptoms H, given a specific illness, are: P(H | A) = 0.85 P(H | B) = 0.90 P(H | C) = 0.70

Assuming that an ill person shows the symptoms H, what is the probability that the person has illness A? Round your answer to four decimal places. ANSWER:

0.3669

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 3:47 AM DATE MODIFIED: 4/22/2019 4:57 AM 120. In the IT company's office, 60 keyboards are mechanical and 40 keyboards are membrane. 30% of the

mechanical keyboards and 60% of the membrane keyboards have a backlight. Do not round your answers.

a. Find the probability that a randomly selected employee uses a mechanical keyboard.

b. Find the probability that a randomly selected employee uses a mechanical keyboard with a backlight.

Chapter 04 - Probability

c. Find the probability that a randomly selected employee uses a mechanical or membrane keyboard with a backlight.

ANSWER:

a. 0.6; b. 0.18; c. 0.42

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 6:06 AM DATE MODIFIED: 2/6/2019 6:10 AM 121. Sarah listens to music on a player. In her playlist, 25 songs last up to 3 minutes, 10 songs last from 4 to 5

minutes, and 5 songs last longer than 5 minutes. Do not round your answers.

a. Find the probability that the song Sarah is listening to lasts less than 5 minutes.

b. Find the probability that the song Sarah is listening to lasts longer than 3 minutes.

ANSWER:

a. 0.875; b. 0.375

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 6:13 AM DATE MODIFIED: 2/6/2019 6:16 AM 122. There are 24 books on the shelf. One-third of the books have a hardcover. The remaining books have a

softcover. Among the softcover books, 50% of the books are horrors, 0.375% of the books are science fiction, and 0.125% of the books are fantasy books. Half of the hardcover books are science fiction books and the other half are fantasy books. Michael randomly picks one book from the shelf. Round your answers to three decimal places if necessary.

a. Find the probability that a randomly picked book has a softcover.

Chapter 04 - Probability

b. Find the probability that a randomly picked book is a science fiction book.

c. Find the probability that a randomly picked book is a science fiction or horror book.

ANSWER:

a. 0.667; b. 0.417; c. 0.75

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 6:17 AM DATE MODIFIED: 2/6/2019 6:20 AM 123. Nicole starts doing shooting sport. Shooting a bow, she hits the target with probability 0.5. If Nicole shot

twice, list the simple events using a tree diagram. Do not round your answers.

a. Find the probability that Nicole hit the target only once in two shots.

b. Find the probability that Nicole hit the target twice in two shots.

ANSWER:

a. 0.5; b. 0.25

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 6:20 AM DATE MODIFIED: 2/6/2019 6:23 AM 124. The dish of the day in the restaurant is selected randomly from three possible options. With the same

probability it can be pasta, roast beef, or salmon tacos. Use a tree diagram to find the probability that the dish of the day will be the same for two consecutive days.

Chapter 04 - Probability

Round your answer to three decimal places.

ANSWER:

0.333

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 6:24 AM DATE MODIFIED: 2/6/2019 6:26 AM 125. A fruit basket contains four apples – two green, one red, and one yellow. Two apples are randomly picked

one at a time from the basket. Round your answers to three decimal places if necessary. a. What is the probability that both apples will be green?

b. What is the probability that the apples will have different colors?

c. What is the probability that the green apples will not be picked?

d. What is the probability that the red apple will not be picked?

ANSWER:

a. 0.167; b. 0.833; c. 0.167; d. 0.5

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 7:44 AM DATE MODIFIED: 2/6/2019 7:46 AM 126. Bob wants to order pizza but he forgot the second digit in the phone number of the delivery.

Round your answers to three decimal places if necessary.

Chapter 04 - Probability

a. What is the probability that Bob will guess the number if he remembers that the second digit was an odd number?

b. What is the probability that Bob will guess the number if he remembers that the second digit was a number greater than 2?

c. What is the probability that Bob will guess the number if he remembers that the second digit was an odd number greater than 2?

ANSWER:

a. 0.2; b. 0.143; c. 0.25

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 7:52 AM DATE MODIFIED: 2/6/2019 7:54 AM 127. A closet contains 20 T-shirts differing in color and material. They could be divided into six categories

shown in the table: red cotton T-shirts, red linen T-shirts, blue cotton T-shirts, blue linen T-shirts, green cotton T-shirts, and green linen T-shirts.

Red Blue Green

Linen 3 5 2

Cotton 6 2 2

Do not round your answers.

a. Find the probability that a randomly selected T-shirt is blue.

b. Find the probability that a randomly selected T-shirt is blue or green.

Chapter 04 - Probability

c. Find the probability that a randomly selected T-shirt is red and made of cotton.

d. Find the probability that a randomly selected T-shirt is blue and made of linen.

e. Find the probability that a randomly selected T-shirt is green and made of cotton or linen.

ANSWER:

a. 0.35; b. 0.55; c. 0.3; d. 0.25; e. 0.2

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 7:55 AM DATE MODIFIED: 2/6/2019 8:01 AM 128. Respondents of three different age groups took part in the survey about technology use. They were

categorized into three groups depending on whether they have a basic cell phone, a smartphone, or they do not have a cell phone at all.

Cell phone, smartphone Cell phone, not smartphone No cell phone

30-49 2,583 326 35

50-64 1,625 503 75

65+ 632 580 304

Round your answers to two decimal places.

a. What is the probability that a randomly selected person from the sample is younger than 50?

b. What is the probability that a randomly selected person from the sample uses a smartphone?

c. What is the probability that a randomly selected person from the sample is younger than 50 and does not use a smartphone?

Chapter 04 - Probability

ANSWER:

a. 0.44; b. 0.73; c. 0.05

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 8:02 AM DATE MODIFIED: 2/6/2019 8:10 AM 129. Tom has 5 coins in his pocket: two quarters, two dimes, and one nickel. He randomly picks 4 coins and

gives them to a street musician. What is the probability that Tom will not give the musician a nickel? Do not round your answer.

ANSWER:

0.2

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 8:11 AM DATE MODIFIED: 2/6/2019 8:12 AM

Chapter 05 - Discrete Probability Distributions 1. Relative frequency histograms are constructed for a sample of n measurements drawn from the population,

while the probability histogram is constructed as a model for the entire population of measurements. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 8:44 AM DATE MODIFIED: 2/4/2019 8:44 AM 2. The probability distribution for a discrete variable x is a formula, a table, or a graph providing p(x), the

probability associated with each of the values of x. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 3. A random variable is any variable the numerical value of which is determined by a random experiment, and,

thus, by chance. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 4. A discrete random variable is countable because the variable can assume values only at specific points on a

scale of values, with inevitable gaps in-between. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 3/29/2019 10:57 AM 5. A table, graph, or formula that associates each possible value of a discrete random variable, x with its

Chapter 05 - Discrete Probability Distributions

probability of occurrence, p(x), is called a discrete probability distribution. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 6. There are two types of random variables: discrete and continuous. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 7. If x is a discrete random variable, then x can only take one of two possible values. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 4/17/2019 11:57 AM 8. The number of students living off-campus is an example of a discrete random variable. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 9. The time required to assemble a computer is an example of a discrete random variable. a. True b. False ANSWER: False

Chapter 05 - Discrete Probability Distributions POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 10. The number of homes sold by a real estate agency in a three week period is an example of a continuous

random variable. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 11. If the mean of the random variable x is larger than the mean of the random variable y, then the variance of x

must be larger than the variance of y. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 3/29/2019 11:07 AM 12. The graph of a discrete random variable looks like a histogram where the probability of each possible

outcome is represented by the area under the bar. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 3/29/2019 11:09 AM 13. The weight of a box of candy bars is an example of a discrete random variable since there is only a specific

number of bars in the box. a. True b. False ANSWER: POINTS:

False 1

Chapter 05 - Discrete Probability Distributions QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 3/29/2019 11:11 AM 14. Which of following statements is true regarding the probability distribution for a discrete random variable

X? a. The probabilities must be nonnegative. b. The probabilities must sum to 1. c. The random variable must take on positive values between 0 and 1. d. Both the probabilities must be nonnegative and the probabilities must sum to 1. e. Both the probabilities must be nonnegative and the random variable must take on positive values

between 0 and 1. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 15. A table, a formula, or a graph that shows all possible values of a random variable x with their associated

probabilities P(x) is called: a. a discrete probability distribution b. a continuous probability distribution c. a bivariate probability distribution d. a law of total probability e. all of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 3/29/2019 11:23 AM 16. The expected number of heads in 500 tosses of an unbiased coin is: a. 150 b. 200 c. 250 d. 300 e. 500 ANSWER: POINTS:

c 1

Chapter 05 - Discrete Probability Distributions QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 17. Which of the following is a required condition for the distribution of a discrete random variable that can

assume values

a. b. c.

Both

and

are required conditions.

d. e. None of these is a required condition. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 18. Which of the following correctly describes the nature of discrete quantitative variables? a. They are characteristics possessed by persons or objects, called elementary units, in which we are

interested. b. They can assume values only at specific points on a scale of values, with inevitable gaps between successive observations c. When dealing with such variables, we can count all possible observations and, with some exceptions, that count leads to a finite result. d. Is correctly described by “they are characteristics possessed by persons or objects, called elementary units, in which we are interested” and “when dealing with such variables, we can count all possible observations and, with some exceptions, that count leads to a finite result.” e. All of these. ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 19. The mean of a discrete random variable x: a. is denoted by b. is denoted by E(x), because it is the value of x one can expect to find on average by numerous

repetitions of the random experiment that generates the variable's actual values

Chapter 05 - Discrete Probability Distributions c. is correctly described by both “is denoted by ” and “is denoted by E(x), because it is the value of x

one can expect to find on average by numerous repetitions of the random experiment that generates the variable's actual values” d. is always = 0 e. is none of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 20. The probability distribution of the number of accidents in Grand Rapids, Michigan, each day is given by

x P(x)

0 .20

1 .15

2 .25

3 .15

4 .20

5 .05

This distribution is an example of: a. continuous probability distribution b. discrete probability distribution c. conditional probability distribution d. an expected value distribution e. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 3/29/2019 11:30 AM 21. The probability distribution of the number of accidents in Grand Rapids, Michigan, each day is given by

x P(x)

0 .20

1 .15

2 .25

3 .15

4 .20

5 .05

Based on this distribution, the expected number of accidents in a given day is: a. 4.62 b. 1.47 c. 2.15 d. 1.81 e. 1 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False

Chapter 05 - Discrete Probability Distributions DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 22. The probability distribution of the number of accidents in Grand Rapids, Michigan, each day is given by

x P(x)

0 .20

1 .15

2 .25

3 .15

4 .20

5 .05

Based on this distribution, the standard deviation of the number of accidents per day is approximately: a. 6.95 b. 2.33 c. 2.64 d. 1.53 e. 15 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 4/17/2019 12:36 PM 23. Which of the following statements is false? a. The mean of a discrete probability distribution is equal to the square root of the variance. b. The expected value of a discrete probability distribution is the long-run average value if the

experiment is to be repeated many times. c. The standard deviation of a discrete probability distribution measures the average variation of the random variable from the mean. d. All of the above. e. None of these. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 24. Let x denote the weight gain in pounds per month for a calf. The probability distribution of x is shown

below. x 0 5 10 15

p(x) 0.1 0.5 0.3 0.1

a. Find the average weight gain in pounds per month for a calf.

Chapter 05 - Discrete Probability Distributions

b. Find the variance of the weight gain.

c. What is

d. What is

e. What is

ANSWER:

a. 7; b. 16; c. 0.4; d. 0.6; e. 0.5

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 25. The random variable x is defined as the number of mistakes made by a typist on a randomly chosen page of

a physics thesis. The probability distribution follows. x 0 1 2 3

p(x) 0.3 0.4 0.2 0.1

Round your answers to four decimal places, if necessary. a. What is E(x)?

b. Find .

c. Find P(x < 1).

Chapter 05 - Discrete Probability Distributions

d. Find

e. In what fraction of pages in the thesis would the number of mistakes made be within two standard deviations of the mean?

ANSWER:

a. 1.1; b. 0.9434; c. 0.3; d. 0.9; e. 0.9

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 4/2/2019 3:15 AM 26. The probability distribution of your winnings at a casino's card game is shown below.

x $0 $1 $2 $5

p(x) 0.1 0.4 0.2 0.3

a. What is the chance you win more than $1 if you play just once?

b. How much should you expect to win if you play the game once?

c. Find the probability that your winning falls into the interval

ANSWER:

a. 0.5; b. $2.3; c.0.2

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:22 AM

Chapter 05 - Discrete Probability Distributions DATE MODIFIED:

4/2/2019 5:03 AM

27. Let x be a random variable with the following distribution:

x -10 -5 0 5 10

p(x) 0.1 0.3 0.1 0.3 0.2

Round your answers to three decimal places, if necessary. a. Find the expected value of x.

b. Find the standard deviation of x.

c. What is the probability that x is further than one standard deviation from the mean?

ANSWER:

1.0; 6.633; 0.3

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 4/2/2019 3:19 AM 28. The neighborhood deli specializes in New York Style Cheesecake. The cheesecakes are made fresh daily

and any unsold cheesecake is donated to the Salvation Army soup kitchen to feed the homeless. Each cheesecake costs $5 to make and sells for $11. The daily demand for cheesecake (the number the deli could sell if they had a cheesecake for everyone who wanted one) has the following distribution. x 0 1 2 3

p(x) 0.0 0.5 0.3 0.2

a. What is the expected demand for cheesecake?

Chapter 05 - Discrete Probability Distributions

b. What is the expected daily profit? $ c. What is the probability that deli donates less than 2 cheesecakes? $ ANSWER:

a. 1.7; b. $10.2; c.0.5

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 4/4/2019 8:12 AM 29. Approximately 5% of the bolts coming off a production line have serious defects. Two bolts are randomly

selected for inspection. Find the probability distribution for x, the number of defective bolts in the sample. Do not round your answers. a. P(x = 0) = P(both bolts are not defective)

b. P(x = 1) = P(one bolt is defective)

c. P(x = 2) = P(both bolts are defective)

d. Find E(x).

e. Find

ANSWER:

a. 0.9025; b. 0.095; c. 0.0025; d. 0.1; e. 0.095

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic

Chapter 05 - Discrete Probability Distributions DATE CREATED: DATE MODIFIED:

2/6/2019 10:22 AM 4/2/2019 3:22 AM

30. In the "Quick Draw" casino card game, a player chooses one card from a deck of 52 well-shuffled cards. If

the card the player selects is the king of hearts, the player wins $104; if the card is an ace, the player wins $78; if the card selected is anything else, the player loses $13. Considering a negative amount won't be a loss, how much should the player expect to win in one play of "Quick Draw"? Do not round your answer. $ ANSWER:

-3.75

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 4/2/2019 3:27 AM 31. Let the random variable x represent the number of cars owned by a family. Assume that x can take on five

values: 0, 1, 2, 3, 4. A partial probability distribution is shown below: x p(x)

0 0.2

1 0.1

2 0.3

3 ?

4 0.1

a. Find the probability that a family owns three cars.

b. Find the probability that a family owns between 1 and 3 cars, inclusive.

c. Find the probability that a family owns no more than one car.

d. What is the probability that a family owns more than two cars?

e. What is the probability that a family owns at most 3 cars?

ANSWER:

a. 0.3; b. 0.7; c. 0.3; d. 0.4; e. 0.9

POINTS: QUESTION TYPE:

1 Subjective Short Answer

Chapter 05 - Discrete Probability Distributions HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 4/17/2019 12:40 PM 32. From experience, a shipping company knows that the cost of delivering a small package within 24 hours is

$16.20. The company charges $16.95 for shipment but guarantees to refund the charge if delivery is not made within 24 hours. If the company fails to deliver only 3% of its packages within the 24-hour period, what is the expected gain per package? Do not round your answer.

ANSWER:

$0.219

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 4/2/2019 4:22 AM 33. A binomial random variable is an example of a discrete random variable. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 34. In a binomial experiment, the probability of success is the same on every trial. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 35. A coin toss experiment represents a binomial experiment only if the coin is balanced, i.e., p = 0.5. a. True b. False ANSWER: False POINTS: 1

Chapter 05 - Discrete Probability Distributions QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 36. A jug contains 5 black marbles and 5 white marbles well mixed. A marble is removed and its color noted. A

second marble is removed, without replacing the first marble, and its color is also noted. If x is the total number of black marbles in the two draws, then x has a binomial distribution. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 37. As a rule of thumb, if the sample size n is large relative to the population size N in particular, if n / N 0.05

then the resulting experiment will not be binomial. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 38. The binomial random variable is the number of successes that occur in a certain period of time or space. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 39. If x is a binomial random variable with n = 20, and p = 0.5, then P(x = 20) = 1.0. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False

Chapter 05 - Discrete Probability Distributions HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 40. The binomial probability distribution is an example of discrete probability distributions. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 41. A binomial probability distribution shows the probabilities associated with possible values of a discrete

random variable that are generated by a binomial experiment. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 42. A binomial experiment is a sequence of n identical trials such that each trial produces one of two outcomes

that are conventionally called success and failure and is independent of any other trial so that the probability of success or failure is constant from trial to trial. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 3/29/2019 12:06 PM 43. The number of successes observed during the n trials of a binomial experiment is called the binomial

random variable. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False

Chapter 05 - Discrete Probability Distributions DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 44. The binomial experiment requires that the successes and failure probabilities be constant from one trial to

the next and also that these two probabilities be equal to each other. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 45. The binomial distribution could be used to describe the spread of tennis balls when the players are serving. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 46. A life insurance salesperson makes 15 sales calls daily. The chance of making a sale on each call is 0.40.

The probability that he will make at most 2 sales is less than 0.10. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 47. The distribution of the number of phone calls to a doctor's office in a one-hour time period is likely to be

described by a binomial distribution. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM

Chapter 05 - Discrete Probability Distributions DATE MODIFIED: 2/6/2019 10:22 AM 48. The number of defects in a random sample of 200 parts produced by a machine is binomially distributed

with p = .03. Based on this information, the expected number of defects in the sample is 6. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 49. The number of defects in a random sample of 200 parts produced by a machine is binomially distributed

with p = 03. Based on this information, the standard deviation of the number of defects in the sample is 5.82. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 3/29/2019 12:10 PM 50. The binomial distribution is used to describe continuous random variables. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 51. Which of the following is a characteristic of a binomial experiment? a. There are n identical trials, and all trials are independent b. Each trial has two possible outcomes which are traditionally labeled "failure" and "success" and the

probability of success p is the same on each trial. c. We are interested in x, the number of successes observed during the n trials. d. All of these are characteristics of a binomial experiment. e. None of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice

Chapter 05 - Discrete Probability Distributions HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 3/29/2019 12:13 PM 52. Which of the following statements regarding a binomial experiment is false, where n is the number of trials,

and p is the probability of success in each trial? a. The n trials are independent. b. The standard deviation is np(1 – p). c. The mean is np. d. There are only two possible outcomes. e. The n trials are independent and the variance is np(1 – p). ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 3/29/2019 12:18 PM 53. For a binomial experiment with n trials, p is the probability of success, q is the probability of failure, and x is

the number of successes in n trials. Which one of the following statements is correct? a. p + q = 1 b. ∑p(x) = 1 for x = 0, 1, ..... , n c. P(x = 0) = d. p + q = 1 and ∑p(x) = 1 for x = 0, 1, ..... , n e. all of these ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 3/29/2019 12:21 PM 54. A telephone survey of American families is conducted to determine the number of children in the average

American family. Past experience has shown that 30% of the families who are telephoned will refuse to respond to the survey. Which of the following statements is not a binomial random variable? a. The number of families out of 50 who respond to the survey. b. The number of families out of 50 who refuse to respond to the survey. c. The number of children in a family which responds to the survey. d. All of these are binomial random variables. e. None of these is a binomial random variable. ANSWER: POINTS:

c 1

Chapter 05 - Discrete Probability Distributions QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:22 AM DATE MODIFIED: 2/6/2019 10:22 AM 55. Which of the following is an example of a binomial experiment? a. A shopping mall is interested in the income level of its customers and is taking a survey to gather

information. b. A business firm introducing a new product wants to know how many purchases its clients will make each year. c. A sociologist is researching an area in an effort to determine the proportion of households with a male head of household. d. A study is concerned with the average number of hours worked by high school students. e. All of these. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 56. The standard deviation of a binomial distribution for which n = 50 and p = 0.15 is: a. 50.15 b. 7.082 c. 6.375 d. 2.525 e. 0.15 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 57. The National Rifle Association chapter in a university town claims 60% of the students at the university

favor gun control. A social scientist at the university conducts a survey of 20 randomly chosen students and finds 9 who favor gun control. Which of the following is a reasonable conclusion? a. There is no reason to doubt the claim. b. The survey results constitute a rare event. c. The NRA's claim is incorrect. d. The true percentage of students who favor gun control must be 45%. e. None of these. ANSWER:

Chapter 05 - Discrete Probability Distributions POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 58. The expected number of heads in 200 tosses of an unbiased coin is: a. 100 b. 50 c. 75 d. 125 e. 200 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 59. The expected value, E(X), of a binomial probability distribution with n trials and probability p of success is: a. n / p b. np(1 – p) c. np d. np – 1 e. n(1 – p) ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 60. Which of the following best describes a binomial probability distribution? a. It is a probability distribution that shows the probabilities associated with possible values of a

discrete random variable that are generated by a binomial experiment. b. It is a probability distribution that shows, for each of a random variable's possible values, the probability of the variable being less than or equal to that value. c. It is a probability distribution that shows the probabilities associated with possible values of a discrete random variable when these values are generated by sampling without replacement and the probability of success, therefore, changes from one trial to the next. d. It is a probability distribution that shows the probabilities associated with possible values of a discrete random variable when these values equal the number of occurrences of a specified event within a specified time or space.

Chapter 05 - Discrete Probability Distributions e. It is a probability distribution that shows, for each of a random variable's possible values, the

probability of the variable is positive. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 61. Which of the following best describes the binomial probability distribution? a. It is a probability distribution that shows the probabilities associated with possible values of a

discrete random variable when these values are generated by sampling without replacement and the probability of success, therefore, changes from one trial to the next. b. It is a probability distribution that shows the probabilities associated with possible values of a discrete random variable when these values equal the number of occurrences of a specified event within a specified time or space. c. It is a probability distribution that shows the probabilities associated with possible values of a continuous random variable when these values equal the number of occurrences of a specified event within a specified time or space. d. It is a probability distribution that shows the probabilities associated with possible values of a continuous random variable that are generated by a binomial experiment. e. None of these. ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/1/2019 8:51 AM 62. The binomial distribution formula: a. computes the number of permutations of x successes (and, therefore, n - x failures) that can be

achieved in n trials of a random experiment that satisfies the conditions of the binomial experiment b. computes the probability of x successes in n trials of a random experiment that satisfies the conditions of a binomial experiment c. produces one of two possible outcomes that are conventionally called success and failure d. computes the probability of x successes when a random sample of size n is drawn without replacement from a population of size N within which M units have the characteristic that denotes success e. does all of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM

Chapter 05 - Discrete Probability Distributions DATE MODIFIED: 2/6/2019 10:23 AM 63. Given that n is the number of trials and p is the probability of success in any one trial of a random

experiment, the expected value of a binomial random variable equals: a. n b. p c. np d. n/p e. n/p(1 – p) ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 64. A manufacturer of tennis balls uses a production process that produces 5 percent defective balls. A quality

inspector takes samples of a week's output with replacement. Using the cumulative binomial probability table available in your text, the inspector can determine which of the following probabilities? a. If 5 units are inspected, the probability of zero units being defective is .774. b. If 10 units are inspected, the probability of 2 units being defective is .374. c. If 15 units are inspected, the probability of 4 units being defective is .999. d. If 20 units are inspected, the probability of 6 units being defective is .0569. e. If 20 units are inspected, the probability of 6 units being defective is .5. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/1/2019 8:00 AM 65. A manufacturer of golf balls uses a production process that produces 10 percent defective balls. A quality

inspector takes samples of a week's output with replacement. Using the cumulative binomial probability table available in your text, the inspector can determine which of the following probabilities? a. If 5 units are inspected, the probability of at most 3 of these units being defective is .984. b. If 10 units are inspected, the probability of 5 or 6 of these units being defective is .002. c. If 15 units are inspected, the probability of at least 10 of these units being defective is .547. d. If 20 units are inspected, the probability of at least 19 of these units being defective is .0009. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM

Chapter 05 - Discrete Probability Distributions DATE MODIFIED: 2/6/2019 10:23 AM 66. It has been alleged that 40 percent of all college students favor Dell computers. If this were true, and we

took a random sample of 50 students, the binomial probability table for cumulative values of x available in your text, would reveal which of the following probabilities? a. The probability of 10 or fewer students in favor is .586. b. The probability of fewer than 20 students in favor is 1.000. c. The probability of more than 15 students in favor is .013. d. All of these. e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 67. Which of the following is not a characteristic of a binomial experiment? a. The experiment consists of n identical and independent trials. b. The probability of success on a single trial remains constant from trial to trial. c. The standard deviation of the binomial random variable is the square root of the mean. d. Each trial results in one of two outcomes. e. All of these. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 68. If the random variable x is binomially distributed with n = 10 and p = .05, then P(x = 2) is: a. 0.599 b. 0.914 c. 0.074 d. 0.55 e. 1.00 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM

Chapter 05 - Discrete Probability Distributions 69. Which of the following statements is true with respect to the binomial distribution? a. The binomial distribution tends to be more symmetric as the probability of success p approaches 0.5. b. As the number of trials increases, the expected value of the random variable decreases. c. As the number of trials increases for a given probability of success, the binomial distribution

becomes more skewed. d. The binomial distribution tends to be more symmetric as the probability of success p approaches 1.0. e. None of these. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 3/29/2019 12:24 PM 70. A fellow student tells you he is working with a discrete random variable, x, which takes on integer values

from 0 to 50 and has a mean of 40 and a variance of 10. Is x a binomial random variable?

Explain.

ANSWER:

No; If x is binomial, it has n = 50 trials, since x = 0, 1, 2, . . ., 50. The binomial mean is np, so if x is binomial, np = 50p = 40, so p = 0.8. If x is binomial with n = 50 and p = 0.8, the variance of x is npq. However, npq = (50) .(0.8) .(0.2) = 8, not 10 as stated in the problem. Thus the random variable x is not binomially distributed.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 71. The taste test for PTC (phenylthiourea) is a common class demonstration in the study of genetics. It is

known 70% of the American people are "tasters" and 30% are "non-tasters." Suppose a genetics class of size 20 does the test to see if they match the U.S. percentage of "tasters" and "non-tasters." (Assume the assignment of students to classes constitutes a random process.) For the random variable x, the number of "non-tasters" in the class, Find P(3 < x < 9). Round your answer to two decimal places.

Chapter 05 - Discrete Probability Distributions

Find the mean of x.

Find the variance of x. Do not round your answer.

ANSWER:

0.78; 6; 4.2

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/2/2019 5:09 AM 72. An oil firm plans to drill 20 wells, each having probability 0.2 of striking oil. Each well costs $20,000 to

drill; a well which strikes oil will bring in $750,000 in revenue. Find the expected gain from the 20 wells.

ANSWER:

$2,600,000

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/3/2019 7:28 AM 73. From past experience, it is known 90% of one-year-old children can distinguish their mother's voice from

the voice of a similar sounding female. A random sample of 20 one-year-olds is given this voice recognition test. (Round your answers to three decimal places if necessary.) Find the probability at least 3 children do not recognize their mother's voice.

Find the probability all 20 children recognize their mother's voice.

Let the random variable x denote the number of children who do not recognize their mother's voice. Find the mean of x.

Chapter 05 - Discrete Probability Distributions

Let the random variable x denote the number of children who do not recognize their mother's voice. Find the variance of x.

Find the probability that at most 4 children do not recognize their mother's voice.

ANSWER:

0.323; 0.122; 2; 1.8; 0.957

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/3/2019 8:13 AM 74. A quiz consists of 15 multiple choice questions. Each question has 5 choices, with exactly one correct

choice. A student, totally unprepared for the quiz, guesses on each of the 15 questions. (Round your answers to three decimal places if necessary.) How many questions should the student expect to answer correctly?

What is the standard deviation of the number of questions answered correctly?

If at least 9 questions must be answered correctly to pass the quiz, what is the chance the student passes?

ANSWER:

3; 1.549; 0.001

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/3/2019 8:13 AM 75. Suppose 40% of the TV sets in use in the U.S. on a particular night were tuned in to game 7 of the World

Series.

Chapter 05 - Discrete Probability Distributions

(Round your answers to three decimal places.) If we were to take a sample of six in-use TV sets that night, what is the probability exactly three are tuned to the World Series?

If, instead, the sample consisted of 15 in-use TVs, what is the probability five or more are tuned to the World Series?

ANSWER:

0.277; 0.783

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/3/2019 8:13 AM 76. In an effort to persuade customers to reduce their electricity consumption, special discounts have been

offered for low consumption customers. In Florida, the EPA estimates that 70% of the residences have qualified for these discounts. (Round your answers to three decimal places.) If we randomly select four residences in Florida, what is the probability exactly two of the four will have qualified for the discounts?

If, instead, a sample of 20 residences is selected, what is the probability 12 or more will have qualified for the discounts?

ANSWER:

0.264; 0.887

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/3/2019 8:11 AM 77. Hotels, like airlines, often overbook, counting on the fact that some people with reservations will cancel at

the last minute. A certain hotel chain finds 20% of the reservations will not be used.

Chapter 05 - Discrete Probability Distributions

If we randomly selected 15 reservations, what is the probability more than 8 but less than 12 reservations will be used? Round your answer to three decimal places.

If four reservations are made, what is the chance fewer than two will cancel? Round your answer to four decimal places.

ANSWER:

0.334; 0.8192

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/3/2019 8:35 AM 78. To determine the effectiveness of a diet to reduce the amount of serum cholesterol, 20 people were randomly

selected to try the diet. After they had been on the diet a sufficient amount of time, their blood was tested to determine the level of serum cholesterol. The clinic running the experiment will approve and endorse the diet only if at least 16 of the 20 people lower their cholesterol significantly. What is the random variable of interest?

What is the probability the clinic will erroneously endorse the diet when, in fact, it is useless in treating high serum cholesterol? Round your answer to three decimal places. [Hint: If the diet is ineffective, a person's cholesterol level is equally likely to go up or down.]

ANSWER:

The number of persons in the study who significantly lowered their serum cholesterol while on the diet.; 0.006

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/3/2019 8:35 AM 79. The local Ford dealership claims 40% of their customers are return buyers, i.e., the customers previously

purchased a Ford vehicle. Let the random variable x be the number of return buyers in a random sample of 10 recent customers. (Round your answers to three decimal places.)

Chapter 05 - Discrete Probability Distributions

Find

Find P(x > 6) = What would you conclude about the accuracy of the dealership's claim if you found 9 repeat buyers in the sample? Explain your reasoning.

ANSWER:

0.627; 0.055; There is reason to doubt the dealership's claim because P(x = 9) = 0.002 if p = 0.40.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/3/2019 8:11 AM 80. An applicant must score at least 80 points on a particular psychological test to be eligible for the Peace

Corps. From nearly 30 years experience, it is known 60% of the applicants meet this requirement. Let the random variable x be the number of applicants who meet this requirement out of a (randomly selected) group of 25 applicants. (Round your answers to two decimal places if necessary.) Find the mean of x.

Find the standard deviation of x.

Using the Empirical Rule, within what limits would you expect most (say, 95%) of the measurements to be?

ANSWER:

15; 2.45; We would expect most of the measurements to be between 10.1 and 19.9 which, since x should be a whole number, translates as between 11 and 19.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/3/2019 8:20 AM 81. A politician claims 55% of the voters will vote for him in an upcoming election. An independent watchdog

Chapter 05 - Discrete Probability Distributions

organization queried a random sample of 500 likely voters, of whom only 249 said they would vote for the politician in question. Do the results of this sample support the politician's claim? [Hint: Binomial distributions with p near 50% are quite mound-shaped.]

Explain.

ANSWER:

No; 249 is more than 2 standard deviations below the mean. Sample results like this would occur approximately 2.5% of the time if the politician's claim of 55% were true.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 82. An American Medical Association study showed 20% of all Americans suffer from high blood pressure.

Suppose we randomly sample ten Americans to determine the number in the sample who have high blood pressure. What is the probability at most two persons have high blood pressure? Round your answer to three decimal places.

If, instead, we sampled 25 Americans, give a reason why the following statement is true: "The probability between one and nine individuals from a sample of 25 would have high blood pressure is at least 0.75." [Hint: For n and p of approximately the sizes given, the distribution would not be particularly symmetric.]

ANSWER:

0.678; Tchebysheff's Theorem says at least 75% of the observations lie within two standard deviations of the mean

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/3/2019 8:34 AM 83. It is known that 70% of the customers in a sporting goods store purchase a pair of running shoes. A random

Chapter 05 - Discrete Probability Distributions

sample of 25 customers is selected. Assume that customers' purchases are made independently, and let x represent the number of customers who purchase running shoes. (Round your answers to three decimal places if necessary.) What is the probability that exactly 18 customers purchase running shoes?

What is the probability that no more than 19 customers purchase running shoes?

What is the probability that at least 17 customers purchase running shoes?

What is the probability that between 17 and 21 customers, inclusively, purchase running shoes?

ANSWER:

0.171; 0.807; 0.677; 0.644

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/3/2019 8:26 AM 84. A Statistics Department is contacting alumni by telephone asking for donations to help fund a new computer

laboratory. Past history shows that 80% of the alumni contacted in this manner will make a contribution of at least $50. A random sample of 20 alumni is selected. Let x represent the number of alumni that make a contribution of at least $50. (Round your answers to three decimal places if necessary.) What is the probability that exactly 15 alumni will make a contribution of at least $50?

What is the probability that between 14 and 18 alumni, inclusively, will make a contribution of at least $50?

What is the probability that less than 17 alumni will make a contribution of at least $50?

Chapter 05 - Discrete Probability Distributions

What is the probability that more than 15 alumni will make a contribution of at least $50?

How many alumni would you expect to make a contribution of at least $50?

ANSWER:

0.174; 0.844; 0.589; 0.630; 16

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/3/2019 8:28 AM 85. Let x be a binomial random variable with n = 15 and p = 0.20.

Calculate P(x 4) using the binomial formula. Round your answer to four decimal places.

Calculate P(x 4) using the cumulative binomial probabilities table in Appendix I of your book. Round your answer to three decimal places if necessary.

Are the results of your two previous answers very different, or very similar?

Calculate the mean of the random variable x. Round your answer to three decimal places if necessary.

Calculate the standard deviation of the random variable x. Round your answer to three decimal places if necessary.

Fill in the table below. Round your answers to three decimal places if necessary. probability

Chapter 05 - Discrete Probability Distributions

Are the results consistent with Tchebysheff's Theorem?

With the Empirical Rule?

ANSWER:

.8358; .836; Very similar; 3; 1.549; .669; .982; .996; Yes; Yes

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/3/2019 8:33 AM 86. In 1996, the average combined SAT score (math + verbal) for students in the United States was 1013, and

41% of all high school graduates took this test. Suppose that 500 students are randomly selected throughout the United States. Which of the following random variables has an approximate binomial distribution? The number of students who took the SAT.

The scores of the 500 students on the SAT.

The number of students who scored above average on the SAT.

The amount of time it took each student to complete the SAT.

ANSWER:

Binomial distribution; Not a binomial distribution; Binomial distribution; Not a binomial distribution

POINTS:

Chapter 05 - Discrete Probability Distributions QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 87. Car color preferences change over the years and according to the particular model that the customer selects.

In a recent year, 20% of all luxury cars sold were white. Assume that 25 cars of that year and type are randomly selected. Find the probabilities listed below: Define x to be the number of cars that are white. Then p = P(white) = 0.20 and n = 25. Use the cumulative binomial probabilities table in Appendix I of your book. (Round your answers to three decimal places.) At least five cars are white.

At most six cars are white.

Exactly four cars are white.

More than three cars are white.

Between three and five cars (inclusive) are white.

More than 20 cars are not white.

ANSWER:

0.579; 0.780; 0.187; 0.766; 0.519; 0.421

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/3/2019 8:37 AM 88. A new surgical procedure is said to be successful 90% of the time. Suppose the operation is performed five

Chapter 05 - Discrete Probability Distributions

times and the results are assumed to be independent of one another. Find the probabilities listed below: Define x to be the number of successful operations. Then p = P(success) = 0.9 and n = 5. We will use the binomial formula. However, you may also use the cumulative binomial probabilities table in Appendix I of your book to calculate the necessary probabilities. (Round your answers to five decimal places.) All five operations are successful.

Exactly four are successful.

Less than two are successful.

ANSWER:

0.59049; 0.32805; 0.00046

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/3/2019 8:39 AM 89. Four in ten Americans who travel by car look for gas and food outlets that are close to or visible from the

highway. Suppose a random sample of n = 20 Americans who travel by car are asked how they determine where to stop for food and gas. Let x be the number in the sample who respond that they look for gas and food outlets that are close to or visible from the highway. Calculate the mean of x. Do not round your answer.

Calculate the variance of x. Do not round your answer.

Calculate the interval

. Round your answer to three decimal places.

What values of the binomial random variable x fall into this interval?

Chapter 05 - Discrete Probability Distributions

Find

. Round your answer to three decimal places.

How does this compare with the fraction in the interval distributions?

ANSWER:

for any distribution? For mound-shaped

8; 4.8; (3.618, 12.382); whole numbers between 4 and 12, inclusively; 0.963; This value agrees with Tchebysheff's Theorem (at least 3 / 4 of the measurements in this interval) and also with the Empirical Rule (approximately 95% of the measurements in this interval.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/3/2019 8:53 AM 90. Let x be a binomial random variable with n = 20 and p = 0.05.

Calculate using the cumulative binomial probabilities table in Appendix I of your book. Round your answer to three decimal places.

Use the Poisson approximation to calculate

. Round your answer to four decimal places.

Compare your results. Is the approximation accurate?

ANSWER:

0.925; 0.9197; Yes

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/3/2019 8:50 AM 91. A psychiatrist believes that 90% of all people who visit doctors have problems of a psychosomatic nature.

She decides to select 20 patients at random to test her theory. (a) Assuming that the psychiatrist's theory is true, what is the expected value of x, the number of the 20 patients who have psychosomatic problems? Do not round your answer.

Chapter 05 - Discrete Probability Distributions

(b) What is the variance of x, assuming that the theory is true? Do not round your answer.

, assuming that the theory is true. Round your answer to three decimal places.

(d) Based on the probability in part (c), if only 14 of the 20 sampled had psychosomatic problems, what conclusions would you make about the psychiatrist's theory?

(e) Explain.

ANSWER:

(a) 18; (b) 1.8; (c) 0.011; (d) The psychiatrist's theory is INCORRECT; (e) Assuming that the psychiatrist's theory is correct, the probability of observing x = 14 or the more unlikely values, x = 0, 1, 2,..,13 is very unlikely. Hence, one of two conclusions can be drawn. Either we have observed a very unlikely event, or the psychiatrist's theory is incorrect and p is actually less than 0.9. We would probably conclude that the psychiatrist's theory is incorrect. The probability that we have made an incorrect decision is 0.011, which is quite small.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/4/2019 5:58 AM 92. About 80% of Florida residents believe that Florida is a nice or very nice place to live. Suppose that five

randomly selected Florida residents are interviewed. (Round your answers to four decimal places.) Find the probability that all five residents think that Florida is a nice or very nice place to live.

What is the probability that at least one resident does not think that Florida is a nice or very nice place to live?

What is the probability that exactly one resident does not think that Florida is a nice or very nice place to live?

Chapter 05 - Discrete Probability Distributions

ANSWER:

0.3277; 0.6723; 0.4096

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/4/2019 6:00 AM 93. The Poisson probability distribution is an example of continuous probability distribution. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 94. The probability distribution of a Poisson random variable provides a good model for data that represent the

number of occurrences of a specified event in a given unit of time or space. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 95. In a Poisson problem, x represents the number of events occurring in a period of time or space during which

an average of such events can be expected to occur. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 96. The Poisson probability distribution provides good approximations to binomial probabilities when n is large

and

is small, preferably with np < 7.

Chapter 05 - Discrete Probability Distributions a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 97. The Poisson distribution is applied to events for which the probability of occurrence over a given span of

time, space, or distance is large. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 98. The mean and variance of the Poisson distribution are equal. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 99. Poisson distribution is appropriate to determine the probability of a given number of defective items in a

shipment. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 100. The Poisson distribution is applied to events for which the probability of occurrence over a given span of

time, space, or distance is very small. a. True

Chapter 05 - Discrete Probability Distributions b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 101. The mean of a Poisson distribution, where is the average number of successes occurring in a specified

interval, is

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 102. The Poisson probability distribution is an example of a discrete probability distribution. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/2/2019 2:19 AM 103. The Poisson random variable is the number of successes achieved when a random sample of size n is drawn

without replacement from a population of size N within which M units have the characteristic that denotes success. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 104. A Poisson process is the occurrence of a series of events of a given type in a random pattern over time

or space such that (1) the number of occurrences within a specified time or space can equal any integer between zero and infinity, (2) the number of occurrences within one unit of time or space is independent of that in any

Chapter 05 - Discrete Probability Distributions

other such (non-overlapping) unit, and (3) the probability of occurrences is the same in all such units. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 105. The Poisson parameter is the mean number of occurrences of an event per unit of time or space during the

Poisson process. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 106. The Poisson probability tables list the probabilities of x occurrences in a Poisson process for various values

of , the mean number of occurrences. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 107. Which of the following experiments can be modeled by the Poisson distribution? a. The number of calls received by a switchboard during a given period of time. b. The number of bacteria per small volume of fluid. c. The number of customer arrivals at a checkout counter during a given minute. d. The number of customer arrivals at a checkout counter during a given hour. e. All of these. ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM

Chapter 05 - Discrete Probability Distributions 108. Given a Poisson random variable x, where the average number of times an event occurs in a certain period

of time is 2.5, then P(x = 0) is: a. 2.5 b. 0.0821 c. 1.5811 d. 0.40 e. 1 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 109. Which probability distribution is appropriate when the events of interest occur randomly, independently of

one another, and rarely? a. Binomial distribution b. Poisson distribution c. Hypergeometric distribution d. any discrete probability distribution e. all of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 110. The mean of a Poisson random variable x, where is the average number of times that an event occurs in a

certain period of time or space, is: a. b. c. d.

e. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM

Chapter 05 - Discrete Probability Distributions 111. Which of the following cannot generate a Poisson distribution? a. The number of telephone calls received by a switchboard in a specified time period. b. The number of customers arriving at a gas station on Christmas day. c. The number of bacteria found in a cubic yard of soil. d. The number of children in a family. e. The number of accidents per day on a certain section of a highway. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 112. The Poisson random variable is: a. a continuous random variable with infinitely many possible values b. a discrete random variable with infinitely many possible values c. a continuous random variable with finite number of possible values d. a discrete random variable with finite number of possible values e. all of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 113. The standard deviation of a Poisson distribution, for which is the average number of times that an event

occurs in a certain period of time or space, is given by: a. b. c. d.

e. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 114. Given a Poisson random variable x, where the average number of times an event occurs in a certain period

of time or space is 1.5, then P(x = 2) is:

Chapter 05 - Discrete Probability Distributions a. 0.2231 b. 0.5020 c. 0.2510 d. 0.1116 e. 0.5 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 115. The variance of a Poisson distribution, for which is the average number of times that an event occurs in a

certain period of time or space, is given by: a. b. c. d.

ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 116. Which of the following correctly describes a Poisson random variable? a. It does not generate a binomial either/or outcome because only a single type of outcome or "event" is

occurring during the Poisson process. b. It is not confined to a fixed number of trials, because its value can equal any discrete integer between zero and infinity, along with a continuum of time or space. c. It equals the number of occurrences of a specified event within a specified time or space. d. All of these. e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/2/2019 2:20 AM 117. Given that is the Poisson mean or average in a given unit of time or space and t is the total number of time

or space units examined, the expected value of a Poisson random variable equals:

Chapter 05 - Discrete Probability Distributions a. b. c. d. e. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 118. In a book, 2 misprints occur per 100 pages. Using the cumulative Poisson probability table available in

your text, we can determine which of the following probabilities in a book of 500 pages? a. The probability of finding between 5 and 6 misprints equals .099. b. The probability of finding at least 20 misprints equals .003. c. The probability of finding at least 24 misprints equals .1234. d. The probability of finding at least 20 misprints equals 1. e. The probability of finding at least 24misprints equals 1. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 119. The number of traffic accidents per day on a certain section of highway is thought to be Poisson distributed

with a mean equal to 2.19. Then the standard deviation of the number of accidents is: a. 2.19 b. approximately 4.80 c. approximately 1.48 d. 3.14 e. (2.19) 2 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/2/2019 2:21 AM 120. The number of traffic accidents per day on a certain section of highway is thought to be Poisson distributed

with a mean equal to 2.19. Then the probability of no accidents on this section of highway during one day

Chapter 05 - Discrete Probability Distributions

period is approximately: a. 0.457 b. 0.112 c. 0.318 d. 0.296 e. 0.211 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/2/2019 2:28 AM 121. The number of traffic accidents per day on a certain section of highway is thought to be Poisson distributed

with a mean equal 2.19. Based on this, how many traffic accidents should be expected during a week-long period? a. 15 b. 11 c. 10 d. 12 e. none of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/2/2019 2:54 AM 122. If the standard deviation for a Poisson distribution is known to be 3.60, the expected value of that Poisson

distribution is: a. 3.60 b. approximately 1.90 c. 8.28 d. 12.96 e. 7.2 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM

Chapter 05 - Discrete Probability Distributions 123. Which of the following statements is false with respect to a Poisson distribution? a. The Poisson distribution is an example of a discrete probability distribution. b. The Poisson distribution is more skewed to the right for smaller values of the parameter . c. The Poisson distribution is symmetrical when the value of the parameter is close to 5. d. The mean of the Poisson distribution is equal to the variance. e. All of these. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 124. Let the random variable x have the Poisson distribution with mean 3.

What is the probability x will fall in the interval

ANSWER:

? Round your answer to three decimal places.

0.966

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/4/2019 6:06 AM 125. The number of telephone calls coming into a business' switchboard averages 4 calls per minute. Let x be

the number of calls received. Find P(x = 0). Round your answer to three decimal places.

What is the probability there will be at least one call in a given one-minute period? Round your answer to three decimal places.

What is the probability at least one call will be received in a given two-minute period? Round your answer to six decimal places. ANSWER:

0.018; 0.982; 0.999665

POINTS: QUESTION TYPE: HAS VARIABLES:

1 Subjective Short Answer False

Chapter 05 - Discrete Probability Distributions STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/4/2019 6:11 AM 126. The quality of computer disks is measured by sending the disks through a certifier which counts the

number of missing pulses. A certain brand of computer disks averages 0.1 missing pulse per disk. Let the random variable x denote the number of missing pulses. What is the distribution of x? Type of distribution:

Mean of distribution:

Find the probability the next inspected disk will have no missing pulse. Round your answer to three decimal places.

Find the probability the next disk inspected will have more than one missing pulse. Round your answer to three decimal places.

Find the probability neither of the next two disks inspected will contain any missing pulse. Round your answer to three decimal places.

ANSWER:

Poisson; 0.1; 0.905; 0.005; 0.819

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/4/2019 6:17 AM 127. The number of teleport inquiries x in a timesharing computer system averages 0.2 per millisecond and

follows a Poisson distribution. (Round your answers to three decimal places.) Find the probability no inquiries are made during the next millisecond.

Chapter 05 - Discrete Probability Distributions

Find the probability no inquiries are made during the next 3 milliseconds.

ANSWER:

0.819; 0.549

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/4/2019 6:19 AM 128. Rebuilt ignition systems leave an aircraft repair shop at an average rate of 3 per hour. The assembly line

needs four ignition systems in the next hour. What is the probability they will be available? Round your answer to three decimal places.

ANSWER:

0.353

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/4/2019 6:23 AM 129. Consider an experiment with 25 trials where the probability of success on any trial is 0.01, and let the

random variable x be the number of successes among the 25 trials. Using the Poisson approximation to the binomial, what are: (Round your answers to three decimal places.)

p(0) = p(1) = p(2) = p(3) = ANSWER:

0.779; 0.195; 0.024; 0.002

POINTS: QUESTION TYPE:

1 Subjective Short Answer

Chapter 05 - Discrete Probability Distributions HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/4/2019 6:34 AM 130. The probability the 1993-94 flu vaccine immunizes those receiving it is 0.97. If a random sample of 200

people receive the vaccine, what is the probability the vaccine will be ineffective on at most 5 people? Use the Poisson approximation. Round your answer to three decimal places.

ANSWER:

0.446

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/4/2019 6:36 AM 131. A salesperson has found the probability of making a sale on a particular product manufactured by his or her

company is 0.05. If the salesperson contacts 140 potential customers, what is the probability he or she will sell at least 2 of these products? Use the Poisson approximation. Round your answer to three decimal places.

ANSWER:

0.993

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/4/2019 6:38 AM 132. An eight-cylinder automobile engine has two misfiring spark plugs. The mechanic removes all four plugs

from one side of the engine. (Round your answers to four decimal places if necessary.) What is the probability the two misfiring spark plugs are among those removed?

What is the mean number of misfiring spark plugs?

What is the variance of the number of misfiring spark plugs?

Chapter 05 - Discrete Probability Distributions

ANSWER:

0.2143; 1; 0.4286

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/4/2019 6:51 AM 133. From a group of 10 bank officers, 3 are selected at random to be relocated and supervise new branch

offices. If two of the 10 officers are women and 8 are men, what is the probability exactly one of the officers to be relocated will be a woman? Round your answer to four decimal places.

ANSWER:

0.4667

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/4/2019 6:53 AM 134. A package of six light bulbs contains 2 defective bulbs. If three bulbs are selected for use, find the

probability none are defective.

ANSWER:

0.20

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 135. Students arrive at a health center, according to a Poisson distribution, at a rate of 4 every 15 minutes. Let x

represent the number of students arriving in a 15 minute time period. (Round your answers to three decimal places.) What is the probability that no more than 3 students arrive in a 15 minute time period?

Chapter 05 - Discrete Probability Distributions

What is the probability that exactly 5 students arrive in a 15 minute time period?

What is the probability that more than 5 students arrive in a 15-minute time period?

What is the probability that between 4 and 8 students, inclusively, arrive in a 15-minute time period?

ANSWER:

0.433; 0.156; 0.215; 0.546

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/4/2019 7:01 AM 136. The number of people arriving at a bicycle repair shop follows a Poisson distribution with an average of 5

arrivals per hour. Let x represent the number of people arriving per hour. (Round your answers to three decimal places.) What is the probability that seven people arrive at the bike repair shop in a one hour period of time?

What is the probability that at most seven people arrive at the bike repair shop in a one hour period of time?

What is the probability that more than seven people arrive at the bike repair shop in a one hour period of time?

What is the probability that between 4 and 9 people, inclusively, arrive at the bike repair shop in a one hour period of time?

ANSWER:

0.105; 0.867; 0.133; 0.703

POINTS: 1 QUESTION TYPE: Subjective Short Answer False HAS VARIABLES: STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM

Chapter 05 - Discrete Probability Distributions DATE MODIFIED:

4/4/2019 7:04 AM

137. It was estimated that 2% of a particular 1997 model minivan had incorrectly installed brake lines. Suppose

300 minivans of this model are selected at random. Let x represent the number of minivans with incorrectly installed brake lines. What is the probability that 9 have incorrectly installed brake lines? Use the Poisson approximation. Round your answer to three decimal places.

ANSWER:

0.069

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/4/2019 7:06 AM 138. The number x of people entering the intensive care unit at a particular hospital on any one day has a

Poisson probability distribution with mean equal to four persons per day. (Round your answers to six decimal places if necessary.) What is the probability that the number of people entering the intensive care unit on a particular day is two?

What is the probability that the number of people entering the intensive care unit on a particular day is less than or equal to two?

Is it likely that x will exceed ten?

Explain.

ANSWER:

0.146525; 0.238103; No; The value x = 10 lies 3.0 standard deviations above the mean.

POINTS: 1 QUESTION TYPE: Subjective Short Answer False HAS VARIABLES: STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM

Chapter 05 - Discrete Probability Distributions DATE MODIFIED:

4/4/2019 7:09 AM

139. Insulin-dependent diabetes (IDD) is a common chronic disorder of children. This disease occurs most

frequently in persons of northern European descent. Let us assume that an area in Europe has an incidence of 6 cases per 100,000 per year. Can the distribution of the number of cases of IDD in this area be approximated by a Poisson distribution?

What is the mean?

What is the probability that the number of cases of IDD in this area is less than or equal to 3 per 100,000? Round your answer to three decimal places.

What is the probability that the number of cases is greater than or equal to 3 but less than or equal to 7 per 100,000? Round your answer to three decimal places.

Would you expect to observe 15 or more cases of IDD per 100,000 in this area in a given year?

Why or why not?

ANSWER:

Yes; 6; 0.151; 0.682; No; The probability of observing 15 or more cases per 100,000 in a year is 0.001. This is an occurrence which we would not expect to see very often, if in fact mu = 6

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/4/2019 7:17 AM 140. It is known that between 8 and 10 a.m. on Saturdays, cars arrive at a toll station in Indiana at a rate of 60

per hour. Assume that a Poisson process is occurring and that the random variable x represents the number of cars arriving at the station between 9:00 and 9:05 a.m. (Round your answers to four decimal places if necessary.)

Chapter 05 - Discrete Probability Distributions

What is the expected number of cars arriving at the toll station between 9:00 and 9:05 a.m.?

What is the standard deviation of the number of cars arriving at the toll station between 9:00 and 9:05 a.m.?

Find P(x = 0).

Find P(x = 2).

Find P(x = 5).

Find P(x = 10).

ANSWER:

5; 2.2361; 0.0067; 0.0842; 0.1755; 0.0181

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/4/2019 7:20 AM 141. An automobile service center can take care of 8 cars per day. Assume that the cars arrive at the service

center randomly and independently of each other at a rate of 6 per hour, on average. What is the standard deviation of the number of cars that arrive at the center per hour? Round your answer to three decimal places.

What is the probability of the service center being empty in any given hour? Round your answer to four decimal places.

What is the probability that exactly 6 cars will be in the service center at any point during a given hour? Round your answer to three decimal places.

Chapter 05 - Discrete Probability Distributions

What is the probability that less than 2 cars will be in the service center at any point during a given hour? Round your answer to four decimal places.

ANSWER:

2.449; 0.0025; 0.161; 0.0174

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/4/2019 7:24 AM 142. The hypergeometric probability distribution is an example of a continuous probability distribution. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/4/2019 7:26 AM 143. The hypergeometric probability distribution is an example of a discrete probability distribution. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/4/2019 7:26 AM 144. The hypergeometric probability distribution formula calculates the probability of x successes when a

random sample of size n is drawn without replacement from a population of size N within which M units have the characteristic that denotes success, and N - M units have the characteristic that denotes failure. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM

Chapter 05 - Discrete Probability Distributions 145. The hypergeometric random variable is the number of successes achieved when a random sample of size n

is drawn with replacement from a population of size N within which M units have the characteristic that denotes success. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 146. A hypergeometric probability distribution shows the probabilities associated with possible values of a

discrete random variable when these values are generated by sampling with replacement and the probability of success, therefore, changes from one trial to the next. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 147. A warehouse contains six parts made by company A and ten parts made by company B. If four parts are

selected at random from the warehouse, the probability that none of the four parts is from company A is approximately .1154. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 148. A warehouse contains six parts made by company A and ten parts made by company B. If four parts are

selected at random from the warehouse, the probability that one of the four parts is from company B is approximately .1099. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False

Chapter 05 - Discrete Probability Distributions HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 149. A warehouse contains six parts made by company A and ten parts made by company B. If four parts are

selected at random from the warehouse, the probability that all four parts are from company B is approximately .008. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 150. When sampling without replacement, the appropriate probability distribution is: a. a binomial distribution b. a hypergeometric distribution c. a Poisson distribution d. all of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 151. The hypergeometric probability distribution is identical to: a. the binomial distribution b. the Poisson distribution c. any continuous probability distribution d. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM

152. Using the hypergeometric formula,

a. we calculate the probability of k successes when a random sample of size n is drawn without

Chapter 05 - Discrete Probability Distributions

replacement from a population of size N within which M units have the characteristic that denotes success b. we assume that k = 0, 1, 2, .... n or M (whichever is smaller) c. we assume that n < N and M < N d. all of these are true ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 153. Given that n is the number of trials of a random experiment, N is population size, M is the number of

population units with the "success" characteristic, and p is the probability of success in the first trial, the mean of the hypergeometric random variable's probability distribution always equals: a. n b. np c. n(N/M) d. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 154. The hypergeometric probability distribution: a. provides probabilities associated with possible values of a binomial random variable in situations in

which these values are generated by sampling a finite population b. provides probabilities associated with possible values of a binomial random variable in situations in which sampling is done without replacement c. provides probabilities associated with possible values of a binomial random variable in situations in which the probability of success changes from one trial to the next d. is correctly described by all of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 155. The hypergeometric probability distribution is used rather than the binomial distribution when the sampling

is performed: a. with replacement from a finite population

Chapter 05 - Discrete Probability Distributions b. without replacement from a finite population of size N and that size N is small in relation to the

sample size n namely, n / N .05 c. without replacement from an infinite population d. with replacement from an infinite population ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 156. A small community college in Ohio has four scholarships. If there are twelve applicants (seven are males,

five are females), what is the probability that only female applicants receive scholarships? Suppose that the seven applicants are equally qualified and that no preference is given by the selection committee for choosing either gender. a. approximately .01 b. 1 c. approximately .99 d. Cannot be determined without additional information. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/4/2019 8:52 AM 157. A professor has received a grant to travel to an archaeological dig site. The grant includes funding for five

graduate students. If there are five male and four female graduate students eligible and equally qualified, what is the probability that the professor will select three male and two female graduate students to accompany her to the dig site? Round your answer to four decimal places.

ANSWER: 0.4762 POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/4/2019 7:47 AM 158. Let x be a hypergeometric random variable with N = 12, n = 4, and M = 3.

(Round your answers to four decimal places if necessary.)

Chapter 05 - Discrete Probability Distributions

Calculate p(0).

Calculate p(1).

Calculate p(2).

Calculate p(3).

Calculate the mean.

Calculate the variance.

What proportion of the population of measurements fall into the interval

Into the interval

Do these results agree with those given by Tchebysheff's Theorem?

ANSWER:

0.2545; 0.5091; 0.2182; 0.0182; 1.0; 0.5455; 0.9818; 1.0; Yes

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/4/2019 7:50 AM 159. A company has five applicants for two positions: three women and two men. Suppose that the five

applicants are equally qualified and that no preference is given for choosing either gender. Let x equal the number of men chosen to fill the two positions.

Chapter 05 - Discrete Probability Distributions

What is the mean of the probability distribution of x?

What is the variance of the probability distribution of x?

What is the standard deviation of the probability distribution of x?

ANSWER:

0.8; 0.36; 0.6

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 160. A student has decided to rent three movies for a three-day weekend. If there are 4 action movies and 6

romance movies that are of equal interest to the student, what is the probability that the student will select 1 romance movie and 2 action movies?

ANSWER:

0.30

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 2/6/2019 10:23 AM 161. A random sample of 4 units is taken from a group of 15 items in which 4 units are known to be defective.

Assume that sampling occurs without replacement, and the random variable x represents the number of defective units found in the sample. (Round your answers to four decimal places.) The mean of the random variable x is:

Chapter 05 - Discrete Probability Distributions

The variance of the random variable x is:

P(x = 0) = P(x = 1) = P(x = 2) = P(x = 3) = P(x = 4) = ANSWER:

1.0667; 0.6146; 0.2418; 0.4835; 0.2418; 0.0322; 0.0007

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/4/2019 7:55 AM 162. A college has seven applicants for three scholarships: four females and three males. Suppose that the seven

applicants are equally qualified and that no preference is given by the selection committee for choosing either gender. Let x equal the number of female students chosen for the three scholarships. (Round your answers to four decimal places.) What is the mean of the distribution of x?

What is the variance of the distribution of x?

What is the probability that only one female will receive a scholarship?

What is the probability that two females will receive a scholarship?

What is the probability that none of the three males will receive a scholarship?

Chapter 05 - Discrete Probability Distributions

What is the probability that none of the four females will receive a scholarship?

ANSWER:

1.7143; 0.4898; 0.3429; 0.5143; 0.1143; 0.0286

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 10:23 AM DATE MODIFIED: 4/4/2019 7:57 AM 163. Which of the following is not an example of a random variable? a. x = number of different types of flowers around a randomly selected home. b. x = number of paintings made in the portrait genre in a randomly selected art gallery. c. x = sum of the numbers on the two upper faces when a pair of dice is tossed. d. x = number of words on the thirtieth page of the book "Alice's Adventures in Wonderland". e. x = number of passing by cars during a randomly selected time period. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 3:54 AM DATE MODIFIED: 2/6/2019 3:57 AM 164. Let x be a random variable and p(x) be the probability associated with each value x. Which of the following

describes the two requirements for a discrete probability distribution? a. b. c. d. e.

and and and and and

ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 3:59 AM DATE MODIFIED: 2/6/2019 4:22 AM

Chapter 05 - Discrete Probability Distributions 165. An experiment was conducted where rats could choose to enter one of two corridors, A or B. A random

sample of three rats is selected. Let x = number of rats that select corridor B. Assuming the rats select their favorite corridor independently of one another and that the two corridors are equally likely to be selected, find the probability distribution of x.

a. P(0) =

b. P(1) =

c. P(2) =

d. P(3) = e. What is the probability that at most one rat selects corridor B?

f. What is the probability that at least one rat selects corridor B?

ANSWER:

a. 0.125; b. 0.375; c. 0.375; d. 0.125; e. 0.50; f. 0.875

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 4/22/2019 2:33 AM DATE MODIFIED: 4/22/2019 2:35 AM 166. Dell computer owners are very faithful. Despite reporting problems with their current systems, 90% of Dell

owners said they would buy another computer from the company, based on the service they received. Suppose you randomly select three current Dell computer users and ask them whether they would buy another Dell computer system. Find the probability distribution for x, the number of Dell users in the sample of three who would buy another Dell computer. a. p(0) =

b. p(1) =

c. p(2) =

Chapter 05 - Discrete Probability Distributions d. p(3) = e. What is the probability that exactly one of the three Dell computer users would buy another Dell computer?

f. What is the probability that at least two of the three Dell computer users would buy another Dell computer? g. What are the population values for the random variable x? Mean: Variance: Standard deviation: ANSWER:

a. 0.001; b. 0.027; c. 0.243; d. 0.729; e. 0.027; f. 0.972; g. 2.7; 0.27; 0.5196

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 4/22/2019 5:02 AM DATE MODIFIED: 4/22/2019 5:04 AM

Chapter 06 - The Normal Probability Distribution 1. If x denotes a continuous random variable, P(x = c) = 0 for every number c. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 2. For a continuous random variable x, P(6 < x < 8) is represented by the area under the probability function

over the interval from 6 to 8. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 3. A normal random variable x is standardized by expressing its value as the number standard deviations

to the right or left of its mean . a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 4. The mean, median, and standard deviation of a normally distributed random variable are all at the same

position on the horizontal axis since the distribution is symmetric. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 5. For a continuous random variable x, the probabilities P(0 x 1) and P(0 < x < 1) are always equal.

it lies

Chapter 06 - The Normal Probability Distribution a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 6. Any continuous random variable cannot take on negative values. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 7. For any continuous random variable x, P(x = 5) = 1 is always true. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 8. Continuous random variables can assume infinitely many values corresponding to points on a line interval. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 9. The relative frequency associated with a particular class in the population is the fraction of measurements in

the population falling in that class. a. True b. False ANSWER:

True

Chapter 06 - The Normal Probability Distribution POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 10. The relative frequency associated with a particular class in the population is the probability of drawing a

measurement from that class. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 11. The total area under the curve f(x) of any continuous random variable x is equal to one. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 12. The normal probability distribution is important because a large number of random variables observed in

nature possess a frequency distribution that is approximately mound-shaped and can be modeled by a normal probability distribution. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/2/2019 6:07 AM 13. The left half of the normal curve is slightly smaller than the right half. a. True b. False ANSWER: False POINTS: 1

Chapter 06 - The Normal Probability Distribution QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 14. Using the standard normal curve, the area between z = 0 and z = 2.2 is 0.4861. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/19/2019 2:04 PM 15. The shape of the normal probability distribution is determined by the population standard deviation

. Small values of reduce the height of the curve and increase the spread; large values of increase the height of the curve and reduce the spread. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 16. The proportion of the total area under the normal curve that lies within one standard deviation of the mean is

approximately 0.75. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 17. Given a normal random variable x with mean and standard deviation

variable associated with x is a. True b. False ANSWER:

True

, the standard normal random

Chapter 06 - The Normal Probability Distribution POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 18. Given a normal random variable x with mean and standard deviation

, the mean of the standard normal

random variable z associated with x is 1. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 19. Given a normal random variable x with mean and standard deviation

, the variance of the standard normal

random variable z associated with x is 0. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 20. Given a normal random variable x with mean of 82 and standard deviation of 12, the value of the standard

normal random variable z associated with x = 70 is smaller than zero. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 21. Given a normal random variable x with mean of 70 and standard deviation of 12, the value of the standard

normal random variable z associated with x = 82 is larger than zero. a. True b. False ANSWER:

True

Chapter 06 - The Normal Probability Distribution POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 22. A continuous random variable x is normally distributed with a mean of 1200 and a standard deviation of

150. Given that x = 1410, its corresponding z-score is 1.40. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 23. Given that z is a standard normal random variable, a negative value of z indicates that the standard deviation

of z is negative. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 24. Given that z is a standard normal random variable, a value of z that is equal to zero indicates that the

standard deviation of z is also zero. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/22/2019 5:49 AM 25. If x is a normal random variable with mean of 2 and standard deviation of 5, then P(x < 3) = P(x > 7). a. True b. False ANSWER: False POINTS: 1

Chapter 06 - The Normal Probability Distribution QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 26. If x is a normal random variable with mean = 4 and standard deviation

= 2, and Y is a normal random variable with mean = 10 and standard deviation = 5, then P(x < 0) = P(Y < 0). a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 27. Using the standard normal curve, the area between z = –1.50 and z = 1.50 is 0.4332. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 28. Let

be a z-score that is unknown but identifiable by position and area. If the area to the right of 0.8849, the value of is 1.2.

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 29. Let

and +

be a z-score that is unknown but identifiable by position and area. If the symmetrical area between − is 0.903, the value of is 1.66.

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False

Chapter 06 - The Normal Probability Distribution HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/22/2019 6:01 AM 30. The z-score representing the 10th percentile of the standard normal curve is −1.28. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/22/2019 6:05 AM 31. Using the standard normal curve, the z-score representing the 95th percentile is 1.645. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 32. The mean and variance of any normal distribution are always zero and one, respectively. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 33. A continuous random variable x is normally distributed with a mean of 100 and a standard deviation of 20.

Given that x = 120, its corresponding z-score is –1.0. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/1/2019 5:02 AM

Chapter 06 - The Normal Probability Distribution 34. The z-score representing the 99th percentile of the standard normal curve is 3.0. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 35. Continuous random variables can assume values at infinitely many points on an interval. The possible values

have no breaks between them. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/1/2019 5:33 AM 36. The observations for continuous random variables are infinite in number. Characteristics, that are measured

in units of money, time, distance, height, volume, length, or weight, exemplify the matter. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/1/2019 5:40 AM 37. A smooth frequency curve that describes the probability distribution of a continuous random variable is

called a standard normal curve. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 38. For a continuous random variable, P(x a) = P(x > a) because P(x = a) = 0. a. True

Chapter 06 - The Normal Probability Distribution b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 39. Examples of continuous probability distributions include the normal probability distribution, the Poisson

probability distribution, and the binomial probability distribution. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 40. The normal random variable's density function is (1) single-peaked above the variable's mean, median, and

mode, all of which are equal to one another, (2) perfectly symmetric about this peaked central value and, thus, bell-shaped, and (3) characterized by tails extending indefinitely in both directions from the center, approaching (but never touching) the horizontal axis, which implies a positive probability for finding values of the random variable anywhere between minus infinity and plus infinity. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 41. A standard normal curve is a normal probability density function with a mean of 1 and a standard deviation

of 0. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 42. For any random variable, P(x a) = P(x < a) because P(x = a) = 0.

Chapter 06 - The Normal Probability Distribution a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 43. For any random variable x, P(x = a) = 0. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 44. For a continuous random variable x, P(x a) = P(x > a) and P(x a) = P(x < a). a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 45. The total area under the normal probability distribution curve is equal to 1. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 46. The normal probability distribution is one of the most commonly used discrete probability distributions. a. True b. False ANSWER: False POINTS: 1

Chapter 06 - The Normal Probability Distribution QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 47. One difference between a binomial random variable x and a standard normal random variable z is that with

the binomial random variable we cannot determine P(x = a), while for the standard normal variable we can determine P(z = a). a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 48. If the mean, median, and mode are all equal for a continuous random variable, then the random variable

must be normally distributed. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 49. The time it takes a student to finish a final exam test is known to be normally distributed with a mean equal

to 84 minutes with a standard deviation equal to 10 minutes. Given this information, the probability that it will take a randomly selected student between 75 and 90 minutes is approximately .0902. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 50. The normal probability distribution is right-skewed for large values of the standard deviation

skewed for small values of . a. True b. False ANSWER:

False

, and is left-

Chapter 06 - The Normal Probability Distribution POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 51. Assume that x is a normally distributed random variable with a mean equal to 13.4 and a standard deviation

equal to 3.6. Given this information and that P(x > a) = .05, the value of a must be 19.322. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 52. Using the standard normal curve, the area between z = 0 and z = 3.50 is about 0.50. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 53. Using the standard normal curve, the probability or area between z = –1.28 and z = 1.28 is 0.3997. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 54. Let

be a z-score that is unknown but identifiable by position and area. If the area to the right of 0.8413, the value of is 1.0. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False

Chapter 06 - The Normal Probability Distribution HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 55. Let

and +

be a z-score that is unknown but identifiable by position and area. If the symmetrical area between – is 0.9544, the value of is 2.0.

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/22/2019 6:47 AM 56. Using the standard normal curve, the z-score representing the 10th percentile is 1.28. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 57. Using the standard normal curve, the z-score representing the 75th percentile is 0.67. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 58. Using the standard normal curve, the z-score representing the 90th percentile is 1.28. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM

Chapter 06 - The Normal Probability Distribution 59. The mean and standard deviation of a normally distributed random variable which has been "standardized"

are one and zero, respectively. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 60. A random variable x is normally distributed with a mean of 150 and a variance of 36. Given that x = 120, its

corresponding z-score is 5.0. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 61. A random variable x is normally distributed with a mean of 250 and a standard deviation of 50. Given that x

= 175, its corresponding z-score is –1.50. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 62. For a normal curve, if the mean is 25 minutes and the standard deviation is 5 minutes, the area to the left of

10 minutes is about 0.50. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM

Chapter 06 - The Normal Probability Distribution 63. For a normal curve, if the mean is 20 minutes and the standard deviation is 5 minutes, the area to the right of

13 minutes is 0.9192. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 64. Given that Z is a standard normal random variable, a negative value of Z indicates that the standard

deviation of Z is negative. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 65. The mean of any normal distribution is always zero. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 66. Which of the following statements is true with regard to continuous random variables? a. The height of the curve shows the probability of an event. b. The probability of exactly an event A occurring is always equal to one. c. Probabilities of events are determined by areas under the curve. d. The probability distribution is always mound-shaped. e. All of these. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM

Chapter 06 - The Normal Probability Distribution DATE MODIFIED: 4/1/2019 5:54 AM 67. Let x be a continuous random variable and let c be a constant. Which of the following statements is false? a. The probability that x assumes a value in the interval

function between and . b. P(x = c) = 0 c. P(x c) = P(x < c) and P(x d. All of the above. e. None of these.

is the area under the probability density

c) = P(x > c)

ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/22/2019 7:11 AM 68. Which of the following describes the discrete probability distributions and continuous probability density

functions incorrectly? a. They both reflect the distribution of a random variable. b. They both produce integer values. c. They both assist in determining the probability of a given outcome. d. They both are relative frequency distributions. e. None of these. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/1/2019 6:06 AM 69. What proportion of the data from a normal distribution is within two standard deviations from the mean? a. 0.4772 b. 0.3413 c. 0.6826 d. 0.9544 e. 0.8824 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM

Chapter 06 - The Normal Probability Distribution DATE MODIFIED: 2/4/2019 9:07 AM 70. The z-score representing the first quartile of the standard normal distribution is: a. 0.67 b. –0.67 c. 1.28 d. –1.28 e. 0.28 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 71. Let

be a z score that is unknown but identifiable by position and area. If the area to the right of 0.7088, then the value of is: a. 1.06 b. –0.55 c. 1.06 d. 0.55 e. 0.70

ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 72. If z is a standard normal random variable, the area between z = 0.0 and z = 1.20 is 0.3849, while the area

between z = 0.0 and z = 1.40 is 0.4192. What is the area between z = –1.20 and z = 1.40? a. 0.0808 b. 0.1151 c. 0.0343 d. 0.8041 e. 0.1646 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM

Chapter 06 - The Normal Probability Distribution 73. If z is a standard normal random variable, the area between z = 0.0 and z = 1.25 compared to the area

between z = 1.25 and z = 2.5 will be: a. larger b. smaller c. the same d. zero e. There is not enough information to answer this question. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 74. If x is a normal random variable with mean of 1228 and a standard deviation of 120, the number of standard

deviations from 1228 to 1380 is: a. 10.233 b. 3.1989 c. 11.50 d. 1.267 e. 2.435 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 75. Using the standard normal table, the total probabilities to the right of z = 2.0 and to the left of z = –2.0 is: a. 0.0228 b. 0.4772 c. 0.9544 d. 0.0456 e. 0.1494 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 76. Let

be a z score that is unknown but identifiable by position and area. If the symmetrical area between a negative and a positive is 0.8132, then the value of is:

Chapter 06 - The Normal Probability Distribution a. z = 1.32 b. z = 0.89 c. z = 2.64 d. z = 1.78 e. z = 8.13 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 77. The z-score representing the third quartile of the standard normal distribution is: a. 0.67 b. –0.67 c. 1.28 d. –1.28 e. 0.33 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 78. Given that Z is a standard normal random variable, P(–1.2 a. 0.8181

Z 1.5) is:

b. 0.4772 c. 0.3849 d. 0.5228 e. 0.2656 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 79. Given that z is a standard normal variable, the value a. –0.70 b. 0.72 c. 0.68

for which P(

) = 0.242 is:

Chapter 06 - The Normal Probability Distribution d. –0.65 e. –0.61 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 80. A standard normal distribution is a normal distribution with: a. a mean of zero and a standard deviation of one b. a mean of one and a standard deviation of zero c. a mean zero and a standard deviation of zero d. a mean of one and a standard deviation of one e. none of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 81. If Z is a standard normal random variable, then P(–1.25 a. 0.6678

–0.75) is:

b. 0.1056 c. 0.2266 d. 0.1210 e. 0.3482 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 82. If the random variable x is normally distributed with a mean of 88 and a standard deviation of 12, then

P(X

96) is: a. 0.2486 b. 0.2514 c. 0.1243 d. 0.4972 e. 0.3398

ANSWER:

Chapter 06 - The Normal Probability Distribution POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 83. Which of the following is always true for all probability density functions of continuous random variables? a. They are symmetrical. b. They are skewed to the right. c. They are skewed to the left. d. The area under the curve is 1.0. e. The area under the curve is 0.1. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 84. Many different types of continuous random variables produce a large variety of probability density

functions, including: a. binomial probability distribution b. hypergeometric probability distribution c. normal probability distribution d. Poisson probability distribution e. both binomial probability distribution and hypergeometric probability distribution ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/1/2019 6:24 AM 85. Which of the following statements about continuous random variables is correct? a. Continuous random variables can assume values at all points on an interval with no breaks between

possible values. b. We can estimate the likelihood of specific values of continuous random variables using one of probability distributions, including the binomial, Poisson, or hypergeometric distributions. c. They are defined at a finite number of specific values. d. All of these. e. None of these. ANSWER:

Chapter 06 - The Normal Probability Distribution POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/1/2019 7:05 AM 86. Continuous random variables, that can assume values at all points on an interval with no breaks between

possible values, are quite common. Examples include: a. profit per dollar of sales b. cost per credit taken by graduate students c. the average time it takes to assemble a car, or write a test d. height e. all of these ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/1/2019 7:40 AM 87. Which of the following describes a continuous random variable correctly? a. We cannot list all possible values of a continuous random variable. b. We cannot list all the probabilities for each of all possible values of the variable. c. We commonly associate probabilities with ranges of values along the continuum of possible values

that the random variable might take on. d. All of these. e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/1/2019 8:07 AM 88. Which of the following describes the normal probability distribution correctly? a. The graph of a normal probability distribution has a single peak above the mean, median, and mode

of a random variable, all of them are equal. b. The graph of a normal probability distribution is a bell-shaped curve, that is perfectly symmetric about the peaked central value. c. The graph of a normal probability distribution has two tails extending indefinitely in both directions from the peaked central value, approaching (but never touching) the horizontal axis. This implies a positive probability for all values of a random variable between minus infinity and plus infinity.

Chapter 06 - The Normal Probability Distribution d. All of these. e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/1/2019 8:59 AM 89. Members of the normal probability distribution family differ from one another only by: a. mean and standard deviation b. median and standard deviation c. mode and standard deviation d. all of the above e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/22/2019 8:05 AM 90. The more peaked a normal curve is, a. the smaller is the value of standard deviation . b. the larger is the value of standard deviation . c. the larger is the value of the mean . d. the more closely the mean, the median, and the mode approach. e. the smaller is the value of the mean . ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/1/2019 9:06 AM 91. Given a normal distribution with a mean of 80 and a standard deviation of 20, an observation of x = 50

corresponds to a standard normal deviate: a. of z = +1.5 b. of z = +3.0 c. of z = –1.5 d. of z = –3.0

Chapter 06 - The Normal Probability Distribution e. of none of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/22/2019 8:21 AM 92. If the standard normal deviate of a random variable value of x = 2 is z = –2, while the standard deviation of

the random variable x equals 2, then the mean of x is: a. 6 b. 4 c. 8 d. 2 e. 0 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 93. Which of the following is not a characteristic of the normal distribution? a. It is symmetric. b. It has a bell-shape. c. Mean = median = mode. d. All of the above. e. None of these. ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/22/2019 8:22 AM 94. Mean, median, and mode are: a. equal to one another in any Poisson probability distribution b. equal to one another in any normal probability distribution c. different measures of center and, therefore, cannot possibly be equal to one another d. different measures of center, but can equal each other only if the probability distribution is negatively

or positively skewed e. equal to one another in any normal probability distribution and different measures of center and,

Chapter 06 - The Normal Probability Distribution

therefore, cannot possibly be equal to one another ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 95. Which of the following probability distributions can be used to describe the distribution for a continuous

random variable? a. Binomial distribution b. Normal distribution c. Poisson distribution d. Hypergeometric distribution e. Both Poisson distribution and Hypergeometric distribution ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 96. If the random variable x is normally distributed with a mean equal to .45 and a standard deviation equal to

.40, then P(x a. 7500 b. 7734 c. 2266 d. 2734 e. 4525

.75) is:

ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 97. If

and are normally distributed random variables with a mean of 95 and a standard deviation of 20, and that and are independent of each other, then P( and < 60) is: a. 0401 b. 0802 c. 2115 d. 0016 e. 1255

Chapter 06 - The Normal Probability Distribution ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 98. Assume that x is normally distributed random variable with a mean of and a standard deviation of .15.

Given this information and that P(x < 2.10) = .025, what is the value of ? a. 2.394 b. 2.104 c. 2.096 d. 1.806 e. 1.235 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/22/2019 8:38 AM 99. If x is normally distributed random variable with a mean of 8.20 and variance of 4.41, and that P(x > b) =

.08, then the value of b is: a. 14.374 b. 3.409 c. 3.448 d. 3.452 e. 8.418 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/22/2019 8:44 AM 100. The time it takes Jessica to bicycle to school is normally distributed with mean 15 minutes and variance 4.

Jessica has to be at school at 8:00 am. What time should she leave her house so she will be late only 4% of the time? a. 15 minutes before 8:00 b.11.5 minutes before 8:00 c. 22 minutes before 8:00

Chapter 06 - The Normal Probability Distribution d. 18.5 minutes before 8:00 e. 10.5 minutes before 8:00 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/22/2019 8:49 AM 101. The time it takes Jessica to bicycle to school is normally distributed with mean 15 minutes and variance 4.

Jessica has to be at school at 8:00 am. Suppose you saw her at class, and she said it took her 23 minutes to get to school that day. Which of the following is a reasonable inference or conclusion? a. Twenty-three minutes to school is not an unusually long commute time. b. A commuting time of 23 minutes is highly unusual or atypical. c. The distribution of commute times must not be normal with mean 15 minutes and standard deviation 2 minutes. d. Both “A commuting time of 23 minutes is highly unusual or atypical” and “The distribution of commute times must not be normal with mean 15 minutes and standard deviation 2 minutes” are feasible conclusions. e. Both “Twenty-three minutes to school is not an unusually long commute time” and “The distribution of commute times must not be normal with mean 15 minutes and standard deviation 2 minutes” are feasible conclusions. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 102. Given that Z is a standard normal random variable, P(–1.0 a. 0.7745

1.5) is:

b. 0.8413 c. 0.0919 d. 0.9332 e. 1.932 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 103. Given that Z is a standard normal variable, the value z for which P(Z a. 0.70

z) = 0.2580 is:

Chapter 06 - The Normal Probability Distribution b. 0.758 c. –0.65 d. 0.242 e. –0.242 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 104. A standard normal distribution is a normal distribution with: a. a mean of zero and a standard deviation of one b. a mean of one and a standard deviation of zero c. a mean of one and a standard deviation of one d. a mean usually larger than the standard deviation e. a mean always larger than the standard deviation ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 105. If Z is a standard normal random variable, then P(–1.75 a. 0.1056

–1.25) is:

b. 0.0401 c. 0.8543 d. 0.0655 e. 0.165 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 106. If Z is a standard normal random variable, then the value z for which P(–z a. 0.3764 b. 1.54 c. 3.08 d. 1.16

z) equals 0.8764 is:

Chapter 06 - The Normal Probability Distribution e. 0.5512 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/1/2019 9:22 AM 107. If the random variable X is normally distributed with a mean of 75 and a standard deviation of 8, then

P(X

75) is: a. 0.125 b. 0.500 c. 0.625 d. 0.975 e. 0.250

ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 108. Given that Z is a standard normal random variable, what is the value z if the area to the right of z is 0.1949? a. 0.75 b. –0.51 c. 0.86 d. –0.68 e. –0.55 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 109. Given that Z is a standard normal random variable, what is the value z if the area to the right of z is 0.9066? a. 1.66 b. –1.32 c. 0.66 d. –0.66 e. 1.02 ANSWER: POINTS:

b 1

Chapter 06 - The Normal Probability Distribution QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 110. Given that Z is a standard normal random variable, P(Z > –1.58) is: a. –0.4429 b. 0.0571 c. 0.9429 d. 0.5571 e. 0.6910 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 111. Given that the random variable X is normally distributed with a mean of 80 and a standard deviation of 10,

P(85

X 90) is: a. 0.5328 b. 0.3413 c. 0.1915 d. 0.1498 e. 0.5841

ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 112. What proportion of the data from a normal distribution is within two standard deviations from the mean? a. 0.3413 b. 0.4772 c. 0.6826 d. 0.9544 e. 0.8290 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM

Chapter 06 - The Normal Probability Distribution DATE MODIFIED: 2/4/2019 9:07 AM 113. Given that Z is a standard normal random variable, the area to the left of a value z is expressed as: a. P(Z z) b. P(Z z) c. P(0 Z z) d. P(Z –z) e. P(z Z 0) ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 114. Which of the following distributions are always symmetrical? a. Exponential b. Normal c. Binomial d. All continuous distributions are symmetrical. e. None of these. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 115. If the z-value for a given value x of the random variable X is z = 1.96, and the distribution of X is normally

distributed with a mean of 60 and a standard deviation of 6, to what x-value does this z-value correspond? a. 71.76 b. 67.96 c. 61.96 d. 48.24 e. 54.99 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 116. If Z is a standard normal random variable, the area between z = 0.0 and z = 1.30 is 0.4032, while the area

Chapter 06 - The Normal Probability Distribution

between z = 0.0 and z = 1.50 is 0.4332. What is the area between z = –1.30 and z = 1.50? a. 0.0300 b. 0.0668 c. 0.0968 d. 0.8364 e. 0.1428 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 117. If Z is a standard normal random variable, the area between z = 0.0 and z = 1.50 compared to the area

between z = 1.5 and z = 3.0 will be: a. the same b. larger c. smaller d. zero e. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 118. Which of the following is not true for a normal distribution? a. It is unimodal. b. It is symmetrical. c. It is discrete. d. It has a bell-shape. e. It is unimodal and discrete. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 119. Which of the following distributions is considered the cornerstone distribution of statistical inference? a. Binomial distribution b. Normal distribution

Chapter 06 - The Normal Probability Distribution c. Poisson distribution d. Uniform distribution e. Geometric distribution ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 120. The probability density function f(x) of a random variable X that is normally distributed is completely

determined once the: a. mean and median of X are specified b. median and mode of X are specified c. mean and mode of X are specified d. mean and standard deviation of X are specified e. mode and standard deviation of X are specified ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 121. For some positive value of z, the probability that a standard normal variable is between 0 and z is 0.3770.

The value of z is: a. 0.18 b. 0.81 c. 1.16 d. 1.47 e. 1.12 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 122. For some value of z, the probability that a standard normal variable is below z is 0.2090. The value of z is: a. –0.81 b. –0.31 c. 0.31 d. 1.96

Chapter 06 - The Normal Probability Distribution e. 1.62 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 123. For some positive value of x, the probability that a standard normal variable is between 0 and 2x is 0.1255.

The value of x is: a. 0.99 b. 0.40 c. 0.32 d. 0.16 e. 0.44 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/22/2019 9:21 AM 124. For some positive value of x, the probability that a standard normal variable is between 0 and 1.5x is

0.4332. The value of x is: a. 0.10 b. 0.50 c. 1.00 d. 1.50 e. 2.00 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/22/2019 9:23 AM 125. A random variable x is normally distributed with μ = 100 and

What is the median of this distribution?

Find

= 20.

Chapter 06 - The Normal Probability Distribution

Find

ANSWER:

100; 0.50; 0.1056

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/22/2019 9:27 AM 126. Let z denote a standard normal random variable.

Find P(z > 1.48).

Find P(–0.44 < z < 2.68).

Determine the value of z0 which satisfies P(z

Find P(z < –0.87).

Find P(–1.66 < z

–0.48).

Find z0 such that P(–z0 < z < z0) = 0.901.

Find z0 such that P(z > z0) = 0.0375.

Find z0 such that P(–z0 < z < z0) = 0.7698.

z0) = 0.7995.

Chapter 06 - The Normal Probability Distribution ANSWER:

0.0694; 0.6663; 0.84; 0.1922; 0.2671; 1.65; 1.78; 1.2

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/1/2019 9:57 AM 127. A chemical manufacturer sells its product in steel drums. The net weight of the chemical in the drums has a

normal distribution with mean 310 pounds and standard deviation 4 pounds. The manufacturer guarantees its customers each drum will contain at least 300 pounds of the chemical. What percentage of the drums will satisfy this guarantee?

ANSWER:

0.9938

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 128. The IQ scores for high school graduates is normally distributed with = 104 and

= 16.

Find the probability that a randomly chosen person from this group has an IQ score above 146.08.

What fraction of the IQ scores would be between 96 and 132?

What is the 95th percentile of this normal distribution?

ANSWER:

0.0043; 0.6514; 130.32

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/1/2019 10:27 AM

Chapter 06 - The Normal Probability Distribution 129. Two students are enrolled in an introductory statistics class at the university. The first student is in a

morning section and the second student is in an afternoon section. Assume test scores are normally distributed. In the morning section, the mean was 64 and the standard deviation was 8. In the afternoon section, the mean was 60 and the standard deviation was 7.5. If the student in the morning section takes a midterm exam and earns a score of 76, while the student in the afternoon section takes a midterm exam and earns a score of 72, which student performed better compared to the rest of the group?

Explain.

ANSWER:

Afternoon student; Since the standardized z2 score is larger than z1, we may conclude that the student in the afternoon section performed better compared to the rest of the group.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/1/2019 10:43 AM 130. EPA studies of fuel consumption indicate compact car mileage to be normally distributed with a mean of

25.5 miles per gallon and a standard deviation of 5.0 mpg. What percentage of compact cars gets between 20 and 40 mpg?

ANSWER:

0.8624

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 131. The mean SAT verbal score of next year's entering freshmen at the local college is 600. The college also

knows 69.5% of the students scored less than 625. If the scores are normally distributed, what is the standard deviation of the SAT scores?

ANSWER:

49.02

POINTS: QUESTION TYPE:

1 Subjective Short Answer

Chapter 06 - The Normal Probability Distribution HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 132. The distribution of final exam scores in inferential statistics class is normal with standard deviation 6. Find

the mean score if 93.32% of the students received scores no higher than 90.

ANSWER:

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 133. The scores on an aptitude test are normally distributed with an unknown mean, a variance of 6, and only

7% of the scores below 26. What is the mean score?

ANSWER:

34.88

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/22/2019 9:43 AM 134. A television set manufacturer has found the length of time until the first repair is normally distributed with

a mean of 4.5 years and a standard deviation of 1.5 years. If the manufacturer wants only 10.2% of the first repairs to occur within the warranty period, how long should the warranty be?

years ANSWER:

2.595

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM

Chapter 06 - The Normal Probability Distribution 135. The lifespan of salmon flies is normally distributed with a mean of 60 days and a standard deviation of 20

days. What percentage of a salmon fly population lives less than 12 days?

What percentage of a salmon fly population lives between 80 and 101 days?

Find the value x0 such that 6.3% of a salmon fly population live less than x0 days.

ANSWER:

0.0082; 0.1385; 29.4

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 136. Suppose the amount of heating oil used annually by households in Iowa is normally distributed with mean

200 gallons per household per year and standard deviation 40 gallons of heating oil per household per year. What is the probability a randomly selected Iowa household uses more than 150 gallons of heating oil per year?

What is the probability a randomly selected Iowa household uses between 180 and 300 gallons per year?

If the members of a particular household were scared into using fuel conservation measures by newspaper accounts of the probable price of heating oil next year, and they decided they wanted to use less oil than 97.5% of all other Iowa households currently using heating oil, what is the maximum amount of oil they can use and still accomplish their conservation objective?

ANSWER:

0.8944; 0.6853; 121.6

POINTS:

Chapter 06 - The Normal Probability Distribution QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 137. The useful lifetime of a brand of automobile battery is normally distributed with mean 1,100 days and

standard deviation 80 days. For how long should these batteries be guaranteed if the manufacturer wants to replace only five percent of the batteries sold because they "died" before the guarantee expired?

ANSWER:

968.4

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 138. Let x denote a normal random variable with mean 30 and standard deviation 5. What x-value is the 67th

percentile of this distribution?

ANSWER:

32.2

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 139. Suppose the amount of tar in cigarettes is normally distributed with mean 3.5 mg and standard deviation

0.5 mg. What proportion of cigarettes have a tar content exceeding 4.25 mg?

"Low tar" cigarettes must have tar content below the 25th percentile of the tar content distribution. What is the value, which is the 25th percentile of the tar content distribution?

Chapter 06 - The Normal Probability Distribution ANSWER:

0.0668; 3.165

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 140. The annual rainfall in a particular area of the country is normally distributed with mean 40 inches and

standard deviation 8 inches. In what proportion of years will the annual rainfall be between 42 and 50 inches?

A drought occurs after a year where the annual rainfall was below the 20th percentile. Find the 20th percentile for the annual rainfall in this area of the country.

ANSWER:

0.2957; 33.28

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 141. The time necessary to assemble a discount store display is normally distributed with = 5 minutes and

= 30 seconds. A large number of potential employees are timed assembling a practice display. How much time (in minutes) should the personnel manager allow the potential employees to assemble the display if the store wants only 80% of the people to complete the task?

minutes ANSWER:

5.42

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 142. For the standard normal probability distribution, find the value z0, such that:

Chapter 06 - The Normal Probability Distribution

P(–z0 > z > z0) = 0.966

P(z > z0) = 0.0174

P(z > z0) = 0.5398

ANSWER:

-2.12; 2.11; -0.10

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/2/2019 1:46 AM 143. A manufacturer of bike racks for cars claims that the assembly time x for a particular model is normally

distributed with a mean of 1 hour and a standard deviation of 0.10 hours. Find the probability that it takes at most 1.1 hours to assemble a bike rack of this model.

Find the probability that it takes longer than 1.2 hours to assemble a bike rack of this model.

Find the probability that it takes between 0.8 hours and 1.1 hours to assemble a bike rack of this model.

Find the assembly time that exceeds 97.5% of all other assembly times for bike racks of this model.

ANSWER:

0.8413; 0.0228; 0.8185; 1.196

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic

Chapter 06 - The Normal Probability Distribution DATE CREATED: DATE MODIFIED:

2/4/2019 9:07 AM 2/4/2019 9:07 AM

144. Suppose x is normally distributed with a mean of 75 and a standard deviation of 4.

Would it be unusual to observe a value x = 59?

Explain.

ANSWER:

Yes; The value x = 59 is 4 standard deviations below the mean of 75, which is very unlikely.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 145. Suppose x is normally distributed with a mean of 75 and a standard deviation of 4.

Find the 90th percentile.

Find the 95th percentile.

Find the 5th percentile.

ANSWER:

80.12; 81.58; 68.42

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM

Chapter 06 - The Normal Probability Distribution 146. The time x a student spends learning a computer software package is normally distributed with a mean of 8

hours and a standard deviation of 1.5 hours. A student is selected at random. What is the probability that the student spends less than 6 hours learning the software package?

What is the probability that the student spends at least 8.5 hours learning the software package?

What is the probability that the student spends between 6.5 and 8.5 hours learning the software package?

ANSWER:

0.0918; 0.3707; 0.4706

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 147. A normal random variable x has an unknown mean and standard deviation

= 2.5. If the probability that x

exceeds 7.5 is 0.8289, find .

ANSWER:

9.875

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 148. A normal random variable x has mean 36.7 and standard deviation 10. Find a value of x that has area 0.01

to its right.

ANSWER:

60.0

POINTS: QUESTION TYPE:

1 Subjective Short Answer

Chapter 06 - The Normal Probability Distribution HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 149. A normal random variable x has mean 54 and standard deviation 15.

Would it be unusual to observe the value x = 0?

Explain.

ANSWER:

Yes; The z-value corresponding to x = 0 is z = –3.60. Since the value x = 0 lies more than three standard deviations away from the mean, it is considered an unusual observation. The probability of observing a value of z as large or larger than z = –3.6 is approximately zero.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 150. A normal random variable x has an unknown mean and standard deviation. The probability that x exceeds 4

is 0.975, and the probability that x exceeds 5 is 0.95. Find .

Find .

ANSWER:

10.222; 3.1745

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM

Chapter 06 - The Normal Probability Distribution 151. For a car traveling 35 miles per hour (mph), the distance required to brake to a stop is normally distributed

with mean of 55 feet and a standard deviation of 8 feet. Suppose you are traveling 35 mph in a residential area and a car moves abruptly into your path at a distance of 65 feet. If you apply your brakes, what is the probability that you will brake to a stop within 45 feet or less?

Within 55 feet or less?

If the only way to avoid a collision is to brake to a stop, what is the probability that you will avoid the collision?

ANSWER:

0.1056; 0.5; 0.8944

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 152. The scores on a national achievement test were normally distributed, with a mean of 550 and a standard

deviation of 112. If you achieved a score of 690, how far, in standard deviations, did your score depart from the mean?

What percentage of those who took the examination scored higher than you?

ANSWER:

1.25; 0.1056

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 153. How does the IRS decide on the percentage of income tax returns to audit for each state? Suppose they do

Chapter 06 - The Normal Probability Distribution

it by randomly selecting 50 values from a normal distribution with a mean equal to 1.25% and a standard deviation equal to 0.4%. What is the probability that a particular state will have more than 2% of its income tax returns audited?

What is the probability that a state will have less than 1% of its income tax returns audited?

ANSWER:

0.0301; 0.266

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/22/2019 10:26 AM 154. Suppose the numbers of a particular type of bacteria in samples of 1 milliliter (ml) of drinking water tend to

be approximately normally distributed, with a mean of 80 and a standard deviation of 10. What is the probability that a given 1-ml sample will contain more than 100 bacteria?

ANSWER:

0.0228

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 155. A car dealership estimated the time of a new car exploitation before it requires a major repair. It is normally

distributed with a mean of 36 months and a standard deviation of 9 months. How many months should the car warranty be, if the dealer wants not more than 5% of the cars to fail before the end of warranty service?

ANSWER:

50.805

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 4/2/2019 2:27 AM

Chapter 06 - The Normal Probability Distribution 156. The average length of time required to complete a college achievement test was found to equal 75 minutes,

with a standard deviation of 15 minutes. When should the test be terminated if you wish to allow sufficient time for 90% of the students to complete the test? (Assume that the time required to complete the test is normally distributed.)

ANSWER:

94.2

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 157. The gestation time for human babies is approximately normally distributed with an average of 280 days and

a standard deviation of 12. Find the upper quartile for the gestation times.

Find the lower quartile for the gestation times.

Would it be unusual to deliver a baby after only 6 months of gestation?

Explain.

ANSWER:

288.04; 271.96; Yes; If you consider a month to be approximately 30 days, the value x = 6(30) = 180 is unusual, since it lies –8.333 standard deviations below the mean gestation time.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM

Chapter 06 - The Normal Probability Distribution 158. The mayor of the city of Detroit was informed that household water usage was a normally distributed

random variable with a mean of 25 gallons and a standard deviation of 4 gallons per day. Find the probability that a random chosen household uses more than 23 gallons per day.

Find the probability that a randomly chosen household uses between 20 and 25 gallons per day.

Find the probability that a randomly chosen household uses fewer than 21 gallons per day.

If the mayor wants to give a tax rebate to the 20% lowest water users, what should the gallons per day cutoff be?

The mayor advertised on a local TV channel for about three weeks his intention to give a tax rebate to the 20% lowest water users. If the advertisement lowered the mean usage of 25 gallons to 21 gallons, what should the gallons per day cutoff be?

ANSWER:

0.6915; 0.3944; 0.1587; 21.64; 17.64

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 159. If Z is a standard normal random variable, find the value z for which:

a. the area between 0 and z is 0.3729.

b. the area to the right of z is 0.7123.

Chapter 06 - The Normal Probability Distribution

c. the area to the left of z is 0.1736.

d. the area to the left of z is 0.7673.

e. the area to the right of z is 0.1841.

f. the area between –z and z is 0.6630.

1.14; –0.56; –0.94; 0.73; 0.90; 0.96

ANSWER:

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 160. If X is a normal random variable with a mean of 45 and a standard deviation of 8, find the following

probabilities: a. P(X

50)

b. P(X

32)

c. P(37

48)

d. P(50

60)

Chapter 06 - The Normal Probability Distribution

e. P(X = 45)

ANSWER:

0.2643; 0.0516; 0.4893; 0.2342; 0.000

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 161. The weights of cans of soup produced by a company are normally distributed with a mean of 15 ounces and

a standard deviation of 0.5 ounces. What is the probability that a can of soup selected randomly from the entire production will weigh at most 14.3 ounces?

Determine the minimum weight of the heaviest 5% of all cans of soup produced.

If 28,390 of the cans of soup of the entire production weigh at least 15.75 ounces, how many cans of soup have been produced?

ANSWER:

0.0808; 15.8225; 425000

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 162. Given that X is a normally distributed random variable with a mean of 50 and a standard deviation of 2,

find the probability that X is between 46 and 52.

Chapter 06 - The Normal Probability Distribution ANSWER:

0.8185

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 163. The owner of a fish market determined that the average weight for a catfish is 3.6 pounds with a standard

deviation of 0.8 pound. Assume the weights of catfish are normally distributed. What is the probability that a randomly selected catfish will weigh more than 4.8 pounds?

What is the probability that a randomly selected catfish will weigh between 3 and 5 pounds?

A randomly selected catfish will weigh more than x pounds to be one of the top 5% in weight. What is the value of x?

A randomly selected catfish will weigh less than x pounds to be one of the bottom 20% in weight. What is the value of x?

Above what weight (in pounds) do 87.70% of the weights occur?

What is the probability that a randomly selected catfish will weigh less than 3.2 pounds?

Below what weight (in pounds) do 83.4% of the weights occur?

ANSWER:

0.0668; 0.7333; 4.916; 2.928; 2.672; 0.3085; 4.376

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM

Chapter 06 - The Normal Probability Distribution DATE MODIFIED:

4/22/2019 10:56 AM

164. Suppose z has a standard normal distribution. Then 28.1% of the possible z values are smaller than:

–0.58

ANSWER:

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 165. Suppose z has a standard normal distribution. Then 85.08% of the possible z values are smaller than:

ANSWER:

1.04

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 166. Suppose z has a standard normal distribution. Then 95.96% of the possible z values are between

and ANSWER:

(symmetrically distributed around the mean). (–2.05, 2.05)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 167. Suppose z has a standard normal distribution. Then 59.9% of the possible z values are between

and ANSWER:

(symmetrically distributed around the mean). (–0.84, 0.84)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM

Chapter 06 - The Normal Probability Distribution 168. Suppose z has a standard normal distribution. Then 16.6% of the possible z values are larger than:

ANSWER:

0.97

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:07 AM DATE MODIFIED: 2/4/2019 9:07 AM 169. Adding or subtracting 0.5 from the binomial random variable x's interval endpoints (i.e., the so-called

continuity correction) improves the normal approximation to the binomial by correcting for or accounting for the "missing" corners of the probability rectangles corresponding to values of x. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 2/4/2019 9:08 AM 170. All binomial distributions can be approximated very closely by normal distributions. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 2/4/2019 9:08 AM 171. The normal approximation to the binomial is appropriate when the number of trials n > 120 and the

probability of success p is near 0.05. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 4/22/2019 11:20 AM

Chapter 06 - The Normal Probability Distribution 172. The total area under any continuous probability curve is equal to one. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 2/4/2019 9:08 AM 173. Even though the normal probability distribution deals with continuous variables, we can use it to

approximate the binomial probability distribution whenever n 30 and also nq 30. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 4/2/2019 6:00 AM 174. Even though the normal probability distribution deals with continuous variables, we can use it to

approximate the binomial whenever np > 5 and also nq > 5. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 2/4/2019 9:08 AM 175. The normal approximation to the binomial distribution works best when the number of trials is large, and

when the binomial distribution is symmetrical (like the normal). a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 2/4/2019 9:08 AM 176. In general, the binomial probability P(X = x) is approximated by the area under a normal curve between x –

Chapter 06 - The Normal Probability Distribution

1 and x + 1. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 4/23/2019 5:46 AM 177. In general, the binomial probability P(X

x) is approximated by the area under the normal curve to the

left of x −.5. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 4/23/2019 5:49 AM 178. In general, the binomial probability P(X

x) is approximated by the area under the normal curve to the

right of x +.5. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 4/23/2019 5:49 AM 179. Even though the normal probability distribution deals with continuous variables, under certain

circumstances, we can use it to approximate various discrete probability distributions. Such use of the normal probability distribution is permissible: a. in the case of binomial probabilities, when np > 5 and also nq > 5 b. in the case of Poisson probabilities, when > 100 c. in the case of hypergeometric probabilities, when np > 1 and also n1 > 1 d. in all of these e. in none of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False

Chapter 06 - The Normal Probability Distribution DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 2/4/2019 9:08 AM 180. Given that X is a binomial random variable, the binomial probability P(X

x) is approximated by the area

under a normal curve to the right of: a. x − 0.5 b. x + 0.5 c. x − 1 d. x + 1 e. x + 0.1 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 4/23/2019 5:39 AM 181. As a general rule, the normal distribution is used to approximate the sampling distribution of the sample

proportion only if: a. the sample size n is greater than 30 b. the sample size n is greater than 100 c. the population proportion p is close to 0.50 d. the underlying population is normal e. np and n(1 − p) are both greater than or equal to 5 ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 4/23/2019 5:39 AM 182. Suppose that the probability p of success on any trial of a binomial distribution equals 0.90. Then for which

of the following number of trials, n, would the normal distribution provide a good approximation to the binomial distribution? a. 5 b. 10 c. 45 d. 50 e. 55 ANSWER: POINTS:

e 1

Chapter 06 - The Normal Probability Distribution QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 4/2/2019 3:09 AM 183. Given that X is a binomial random variable, the binomial probability P(X = x) is approximated by the area

under a normal curve between: a. x − 0.5 and 0.0 b. 0.0 and x + 0.5 c. 1 − x and 1 + x d. x − 0.5 and x + 0.5 e. 0.0 and x + 1 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 4/23/2019 5:40 AM 184. Given that X is a binomial random variable, the binomial probability P(X

x) is approximated by the area

under a normal curve to the left of: a. x b. −x c. x + 0.5 d. x − 0.1 e. −x − 0.1 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 4/23/2019 5:41 AM 185. Consider a binomial random variable x with n = 25 and p = 0.01. Would the normal approximation be

appropriate here?

Why or why not?

Chapter 06 - The Normal Probability Distribution ANSWER:

No; Because p is so small, the distribution of x will be asymmetrical (right-skewed) and the normal curve, being symmetrical, would provide a poor approximation to the distribution of x.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 2/4/2019 9:08 AM 186. A recent survey of university faculty reported, that 55% of students were thinking about transferring to

another profession. Based on this information, what is the expected number of students who thought about changing profession if we randomly sampled 200 faculty members?

What is the approximate probability that 60 or more students from a random sample of 200 would consider transferring to another profession? Give your answer to one decimal place.

ANSWER:

110; 1.0

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 4/2/2019 4:23 AM 187. Past records indicated that 60% of the eligible voters in Michigan voted in the primary election.

What is the expected number of eligible voters in the next primary election for a random sample of 200?

What is the approximate probability that more than 150 from a sample of 200 will vote in the next primary election? Give your answer to one decimal place.

ANSWER:

120; 0

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 4/2/2019 4:22 AM

Chapter 06 - The Normal Probability Distribution 188. Twenty-five psychology instructors have formed a committee to choose a textbook for the next year, and

they have narrowed their decision down to two equally good books, one with a better bibliography and references, and the other with a better format and illustrations. Since the books are considered to be equally good, we will assume the probability an instructor chooses any book is 0.5 and the instructors made decisions independently. Using the binomial distribution, find the probability that 15 or more instructors will choose the book with the better format and illustrations.

Use the normal approximation to the binomial to find the probability that 15 or more instructors will choose the book with the better format and illustrations.

Compare the results in parts (a) and (b). Is the normal approximation a good approximation?

ANSWER:

0.212; 0.2119; Yes

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 4/2/2019 5:43 AM 189. Twenty percent of American men over 30 have high blood pressure. To run an experiment, a researcher

needs to identify at least 15 men with high blood pressure. If the researcher examines 100 men over 30, what is the approximate probability he or she finds enough men with high blood pressure to run the experiment?

ANSWER:

0.9162

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 2/4/2019 9:08 AM 190. Suppose that the current median age of U.S. citizens is 30. If a sample of 500 randomly selected U.S.

citizens is taken, what is the probability that at least 240 of them is under 30 years old?

ANSWER:

0.3023

Chapter 06 - The Normal Probability Distribution POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 4/2/2019 5:34 AM 191. A firm with many traveling salespersons decides to check the salespersons' travel expenses to see if they

are correctly reported. An auditor for the firm selects 200 expense reports at random to audit. What is the probability more than 20% of the sampled reports will be incorrect when, in fact, only 10% of the firm's expense reports are improperly documented?

ANSWER:

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 2/4/2019 9:08 AM 192. A student government representative claims that 55% of the student body of a local university favor a move

to Division I in college football. A random sample of 2000 students is selected. What is the expected number of students that will favor the move to Division I?

What is the approximate probability that less than 1150 students of the 2000 selected will favor the move to Division I?

ANSWER:

1100; 0.9884

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 2/4/2019 9:08 AM 193. Let x be a binomial random variable with n = 25 and p = 0.3.

Is the normal approximation appropriate for this binomial random variable?

Chapter 06 - The Normal Probability Distribution

Find the mean for x.

Find the standard deviation for x.

Use the normal approximation to find

Use the cumulative binomial probabilities table in Appendix 1 of your book to calculate the exact probability, above.

Compare the results of the last two questions. Was your approximation close, or far, from the exact answer?

ANSWER:

Yes; 7.5; 2.291; 0.6156; 0.618; Close

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 2/4/2019 9:08 AM 194. Suppose the records of a motel show that, on the average, 10% of their prospective guests will not claim

their reservation. If the motel accepts 218 reservations and there are only 200 rooms in the motel, what is the probability that all guests who arrive to claim a room will receive one?

ANSWER:

0.834

POINTS: QUESTION TYPE: HAS VARIABLES:

1 Subjective Short Answer False

Chapter 06 - The Normal Probability Distribution STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 2/4/2019 9:08 AM 195. Do Americans tend to vote for the taller of the two candidates in a presidential election? In 30 of our

presidential elections since 1856, 18 of the winners were taller than their opponents. Assume that Americans are not biased by a candidate's height and that the winner is just as likely to be taller or shorter than his opponent. Is the observed number of taller winners in the U.S. presidential elections unusual? Find the approximate probability of finding 18 or more of the 30 pairs in which the taller candidate wins.

Can you conclude that Americans consider a candidate's height when casting their ballot?

ANSWER:

0.1814; No

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 4/22/2019 8:55 PM 196. In a certain population, 18% of the people have Rh-negative blood. A blood bank serving this population

receives 95 blood donors on a particular day. What is the probability that 10 or fewer are Rh-negative?

What is the probability that 15 to 20 (inclusive) of the donors are Rh-negative?

What is the probability that more than 80 of the donors are Rh-positive?

ANSWER:

0.0392; 0.5735; 0.2451

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:08 AM

Chapter 06 - The Normal Probability Distribution DATE MODIFIED:

2/4/2019 9:08 AM

197. The admissions office of a community college in Indiana is asked to accept deposits from a number of

qualified prospective freshmen so that, with probability about 0.95, the size of the freshmen class will be less than or equal to 150. Suppose the applicants constitute a random sample from a population of applicants, 80% of whom would actually enter the freshmen class if accepted. a) How many deposits should the admissions counselor accept?

b) If applicants in the number determined in part (a) are accepted, what is the probability that the freshmen class size will be less than 135?

ANSWER:

177; 0.0918

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 4/22/2019 9:14 PM 198. Historical data collected at First of America Bank in Michigan revealed that 80% of all customers applying

for a loan are accepted. Suppose that 50 new loan applications are selected at random. Find the expected value of the number of loans that will be accepted by the bank.

Find the standard deviation of the number of loans that will be accepted by the bank.

What is the probability that at least 42 loans will be accepted?

What is the probability that the number of loans rejected is between 10 and 15, inclusive?

ANSWER:

40; 2.828; 0.2981; 0.5452

POINTS:

Chapter 06 - The Normal Probability Distribution QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:08 AM DATE MODIFIED: 2/4/2019 9:08 AM 199. The weight in grams of a greeting card in a bookstore is uniformly distributed on the interval from 13 to 25.

What is the probability that the weight of the greeting card is between 16 and 20 grams? a. .66 b. .50 c. .42 d. .25 e. .33 ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/5/2019 10:47 AM DATE MODIFIED: 2/5/2019 10:50 AM 200. The duration of a pet inspection in a veterinary clinic follows an exponential distribution with an average

duration of 25 minutes. What is the probability that a pet inspection lasts less than 10 minutes? a. 6703 b. 0392 c. 3297 d. 9608 e. 0 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/5/2019 10:51 AM DATE MODIFIED: 2/5/2019 10:54 AM

Chapter 07 - Sampling Distributions 1. If a sample of n elements is selected from a population of N elements using a sampling plan in which each of

the possible samples has the same chance of being selected, then the sampling is said to be random and the resulting sample is a simple random sample. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 2. There are four ways of selecting a distinct, unordered sample of size n = 2 without replacement from a

population of size N = 4. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 3. A cluster sample is a simple random sample of clusters from the available clusters in the population. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 4. Nonrandom samples can be described and also be used for making inferences. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 5. A newspaper is trying to decide which comics to carry on a daily basis, which comics to carry only on

Sunday, and which comics to discontinue. The editor invites the readers to "vote" for their preferences by

Chapter 07 - Sampling Distributions

clipping a "ballot" from the editorial page and mailing it in. This is an example of a judgment sample. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 6. Stratified random sampling involves selecting a simple random sample from each of a given number of

subpopulations, called strata. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 7. The publisher of a newspaper decides which articles will be submitted for the consideration of the Pulitzer

Prize committee. This is an example of cluster sampling. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 8. Numerical descriptive measures calculated from a sample are called Statistic. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 9. The latest U.S. census shows the population aged 25 to 40 to be 48% male and 52% female. A market

research firm interested in the buying habits of young adults aged 25 to 40 instructs its interviewers to sample 300 persons, 144 of whom are to be men and 156 of whom are to be women. This is an example of a quota

Chapter 07 - Sampling Distributions

sample. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 10. A convenience sample is a sample that can be easily and simply obtained with random selection. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 11. Judgment sampling allows the sampler to decide who will or will not be included in the sample. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 12. A 1-in-k systematic random sample involves the random selection of one of the first k elements in an

ordered population, and then the systematic selection of every kth element thereafter. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 13. Quota sampling, in which the makeup of the sample must reflect the makeup of the population on some pre-

selected characteristics, often has a nonrandom component in the selection process. a. True

Chapter 07 - Sampling Distributions b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 14. Let xi be 1 if a success occurs and 0 otherwise. Let x = ∑ xi i.e., x is the count of the number of successes in

n trials. If a random sample is taken from a population which contains only zeros and ones, the sample mean is an estimate of the actual proportion of ones in the population. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/1/2019 10:33 AM 15. A group of people who, in response to some general appeal, have selected themselves to participate in a

survey is called a simple random sample. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 16. The simple random sample is a subset of a frame, or of an associated population, chosen in such a fashion

that every possible subset of like size has an equal chance of being selected. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 17. The stratified random sample is a subset of a frame, or of an associated population, chosen by randomly

selecting one of the first k elements and then including every kth element thereafter until the desired sample size has been reached.

Chapter 07 - Sampling Distributions a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 18. If a sample is selected at random, the main reason that the sample mean might be different than the

corresponding population mean is that the sample might be biased. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 19. The shape of the normal distribution is determined by its mean and its standard deviation a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM

20. All sampling plans involve random selection of the sample from the corresponding population. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 21. Which of the following is a correct statement about the stratified random sample? a. It is useful when the frame or population to be sampled is known to contain two or more mutually

exclusive and clearly distinguishable subgroups or strata that differ greatly from one another with respect to some characteristic of interest.

Chapter 07 - Sampling Distributions b. It is useful when the frame or population to be sampled is known to contain two or more mutually

exclusive and clearly distinguishable subgroups or strata that are fairly homogeneous internally. c. It is chosen by taking separate (simple or systematic) random samples from every stratum, often in such a way that the sizes of the separate samples vary with the importance of the different strata. d. All of these are correct statements about this type of sample. e. None of these are correct statements about this type of sample. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 22. Which of the following correctly describes a sample? a. It is a subset of the population of interest. b. Its summary measures are designated by Roman letters (such as for sample mean). c. Its summary measures are called statistic. d. All of these. e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 23. A list of commonly used parameters includes: a. the sample mean b. the sample standard deviation, s c. the sample proportion d. all of these e. none of these ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 24. Which of the following is not a correct statement about the 1-in-k systematic random sample? a. This type of sample has the advantage of being usable even when we do not know the size of the

frame and, thus, cannot label each elementary unit with a number.

Chapter 07 - Sampling Distributions b. This type of sample is a subset of a frame, or of an associated population, chosen by taking separate

censuses in a randomly chosen subset of geographically distinct clusters into which the frame or population is naturally divided. c. This type of sample is a subset of a frame, or of an associated population, chosen by randomly selecting one of the first k elements and then including every kth element hereafter until the desired sample size has been reached. d. This type of sample might be used by a quality inspector who wants to determine the percentage of defective units produced on an assembly line that never shuts down. e. Both “This type of sample is a subset of a frame, or of an associated population, chosen by taking separate censuses in a randomly chosen subset of geographically distinct clusters into which the frame or population is naturally divided” and “This type of sample is a subset of a frame, or of an associated population, chosen by randomly selecting one of the first k elements and then including every kth element hereafter until the desired sample size has been reached” are incorrect. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/1/2019 10:47 AM 25. Identify the sampling design for each of the following.

The Vice President for Academic Affairs of Southern State University decides which research proposals submitted to her by each college dean will be submitted for federal funding consideration.

Every student in an introductory genetics class is assigned a number. The professor then randomly selects ten numbers and surveys the corresponding students.

Class rosters list student names in alphabetical order. A professor wants to select some students to participate in a research project. The professor starts with the 5th name and then selects every 10th student thereafter.

An apartment complex manager randomly selects 10 buildings from the complex of 30 buildings, and then interviews one household from every apartment in the 10 buildings.

The student body of a large law school is comprised of 85% in-state residents and 15% out-of-state residents.

Chapter 07 - Sampling Distributions

An evaluation team wishes to interview 200 alumni from the school. They are instructed to contact 170 in-state alumni and 30 out-of-state alumni.

ANSWER:

Judgment sampling; Simple random sampling; 1-in-k Systematic sampling; Cluster sampling; Quota sampling

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 26. A questionnaire was mailed to 1000 registered municipal voters selected at random. Only 600 questionnaires

were returned, and of the 600 returned, 450 respondents were strongly opposed to a surcharge proposed to support the city Parks and Recreation Department. Are you willing to accept the 75% figure as a valid estimate of the percentage in the city who are opposed to the surcharge?

Why or why not?

ANSWER:

No; The questionnaires that were returned do not constitute a representative sample from the 1000 questionnaires that were randomly sent out.It may be that the voters who chose to return the questionnaire were particularly adamant about the Parks and Recreation surcharge, while the others had no strong feelings one way or the other. The nonresponse of 40% of the voters in the sample will undoubtedly bias the resulting statistic.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 27. A group of medical researchers reported on the accuracy of using magnetic resonance imaging (MRI) to

evaluate ligament sprains and tears on 50 patients. Consecutive patients with acute or chronic knee pain were selected from the clinical practice of one of the researchers and agreed to participate in the study. Describe the sampling plan used to select study participants.

Chapter 07 - Sampling Distributions

What chance mechanism was used to select this sample of 50 individuals with knee pain?

When can valid inferences be made using the results of this study?

ANSWER:

The sample was chosen from patients in the clinical practice of one of the researchers who was willing to participate.; Convenience sampling; Valid inferences can be made from this study only if the convenience sample chosen by the researcher behaves like a random sample. That is, the patients in this particular clinical practice must be representative of the population of patients as a whole. In order to increase the chances of obtaining a sample that is representative of the population of patients as a whole, the researcher might try to obtain a larger base of patients to choose from.Perhaps there is a computerized database from which he or she might select a random sample.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/1/2019 11:09 AM 28. A study of an experimental blood thinner was conducted to determine whether it works better than the

simple aspirin tablet in warding off heart attacks and strokes. The study involved 20,000 people who had suffered heart attacks, strokes, or pain from clogged arteries. Each person was randomly assigned to take either aspirin or the experimental drug for 1 to 3 years. Assume that each person was equally likely to be assigned one of the two medications. Devise a randomization plan to assign the medications to the patients.

Will there be an equal number of patients in each treatment group? Explain.

ANSWER:

Answers will vary. For example: Since each patient must be randomly assigned to either aspirin or the experimental drug with equal probability, assign the digits 0-4 to the aspirin treatment, and the digits 5-9 to the experimental drug treatment. As each patient enters the study, choose a random digit using the table of random numbers and assign the appropriate treatment.; Answers will vary. For example: The randomization scheme in the previous question does not guarantee an equal number of patients in each group.

POINTS: QUESTION TYPE:

1 Subjective Short Answer

Chapter 07 - Sampling Distributions HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/1/2019 11:15 AM 29. The total area under a probability density function curve is a number between 0.5 and 1.0. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 30. If random samples of size n = 36 are drawn from a nonnormal population with finite mean

standard deviation distributed with mean

and , then the sampling distribution of the sample mean is approximately normally and standard deviation

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 31. If random samples of size n = 50 are drawn from a nonnormal population with finite mean =100 and

standard deviation = 20, then, the sampling distribution of the sum of sample measurements approximately normally distributed with mean and standard deviation .

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 32. The spread of the distribution of sample means is considerably less than the spread of the sampled

population. a. True b. False

Chapter 07 - Sampling Distributions ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 33. The most important contribution of the Central Limit Theorem is in statistical inference. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 34. The sampling distribution of the sample mean is exactly normally distributed, regardless of the sample size

n. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 35. According to the Central Limit Theorem, for large samples the standard error of the sample mean is the

population standard deviation divided by the square root of the sample size. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 36. The Central Limit Theorem describes the distribution of the sample mean except for populations that are

normal. a. True b. False ANSWER:

False

Chapter 07 - Sampling Distributions POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 37. The Central Limit Theorem does not apply to the sample means of large samples drawn from a discrete

distribution. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 38. The total area under a probability density function curve is equal to 1.0. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 39. The standard deviation of a statistic that is used to estimate an unknown parameter is called the standard

error of the statistic. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 40. As the sample size increases, the standard error of the sample mean decreases. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False

Chapter 07 - Sampling Distributions HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 41. When all possible simple random samples of size n are drawn from a population that is normally distributed,

the sampling distribution of the sample means will be normal regardless of sample size n. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 42. A summary measure calculated for a population is called a parameter and is designated by Greek letters

(such as μ for mean or p for proportion). a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/1/2019 11:21 AM 43. A sampling distribution is defined as a sample chosen in such a way that every possible subset of like size

has an equal chance of being selected. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 44. A sampling distribution is a probability distribution that shows the likelihood of occurrence associated with

all the possible values of a parameter, which values would be obtained when drawing all possible samples of a given size from a population. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False

Chapter 07 - Sampling Distributions HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 45. The sample standard deviation measures the variability of all possible sample mean values that might be

obtained. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/1/2019 11:22 AM 46. If is the sample mean of a simple random sample taken from a large population and if the N population

values are normally distributed, the sampling distribution of is also normally distributed, regardless of sample size, n. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/1/2019 11:25 AM 47. According to the Central Limit Theorem, any sampling distribution of is considered normal provided

. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 48. According to the Central Limit Theorem, any sampling distribution of sample proportion

np < 5, while a. True b. False ANSWER: POINTS:

False 1

normal provided

Chapter 07 - Sampling Distributions QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 49. A sampling distribution is the distribution of the values that are included in a sample selected randomly from

the population. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 50. In practical business situations, it is very unlikely that a decision maker will actually construct a sampling

distribution of any kind. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 51. The mean for a sample selected randomly from a population is most likely to be lower or higher than the

known value of the population mean. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 52. The sampling distribution of the sample mean is the distribution of all possible sample means that could be

computed from all possible sample of a given size n. a. True b. False ANSWER: POINTS:

True 1

Chapter 07 - Sampling Distributions QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 53. The mean of the sampling distribution of sample mean is equal to the mean of the population from which

the samples are selected to construct the sampling distribution. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 54. If a population standard deviation is equal to 24.8, then the sampling distribution of the sample mean will

have a standard deviation that is less than 24.8 for all possible sample sizes. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 55. The population of Pepsi cans filled by a particular machine is known to be normally distributed with a mean

of 12 ounces and a standard deviation of .16 ounces. Given this information, the sampling distribution of the sample mean for a random sample of 16 cans will also be normally distributed with a standard deviation equal to .04. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/1/2019 11:30 AM 56. The population of Pepsi cans filled by a particular machine is known to be normally distributed with a mean

Chapter 07 - Sampling Distributions b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/1/2019 11:30 AM 57. If a population standard deviation is equal to 50, then the sampling distribution of the sample mean will

have a standard deviation that is less than 50 for all samples of size n 2. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 58. The Central Limit Theorem is used to describe the sampling distributions of statistics, such as and

, when

the population is known to be normally distributed. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 59. The population of incomes in a community college in Iowa is thought to be highly skewed to the right with a

mean equal to $38,765 and a standard deviation equal to $2,640. Based on this information, if a sample of size 36 is selected at random, then the highest sample mean that we would expect to see would be approximately $40,085. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 60. In order to use the Central Limit Theorem to describe the sampling distribution of the sample mean , the

Chapter 07 - Sampling Distributions

sample size n must be 30 or more. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 61. A population with a large standard deviation will have a sampling distribution that is more spread out for a

given sample size than a similar population with a small standard deviation. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 62. Which of the following statements about the Central Limit Theorem (CLT) is correct? a. The CLT states that the sample mean is always equal to the population mean, . b. The CLT states that the sampling distribution of the population mean is approximately normal,

provided that

c. The CLT states that the sampling distribution of the sample mean is approximately normal for large

sample sizes (

d. The CLT states that the sample mean is equal to the population mean , provided that . e. The CLT states that the sampling distribution of the population mean is approximately normal,

provided that

ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 63. Consider a large population with a mean of 150 and a standard deviation of 27. A random sample of size 36

is taken from this population. The standard error of the sampling distribution of sample mean is equal to: a. 4.17 b. 4.50 c. 5.20 d. 5.56

Chapter 07 - Sampling Distributions e. 6.00 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 64. Random samples of size 36 each are taken from a large population whose mean is 120 and standard

deviation is 39. The mean and standard error of the sampling distribution of sample mean, respectively, are: a. 120 and 39 b. 120 and 6.5 c. 120 and 5.5 d. 39 and 120 e. 6.5 and 120 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 65. Suppose that random sample is drawn from a nonnormal population. Which minimum value of the sample

sizes will produce a sampling distribution of the sample mean that is approximately normal? a. 10 b. 20 c. 30 d. 40 e. 50 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/1/2019 12:06 PM 66. If all possible samples of size n are drawn from a large population with a mean of 20 and a standard

deviation of 5, then the standard error of the sample mean equals 1.0 only for samples of size: a. 15 b. 20 c. 25 d. 30

Chapter 07 - Sampling Distributions e. 35 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 67. The standard error of a statistic used as an estimator of a population parameter is: a. the standard deviation of the sampling distribution of the statistic b. the variance of the sampling distribution of the statistic c. the same value as the population standard deviation d. the same value of the population variance e. the same value of the population mean ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 68. If all possible samples of size n are drawn from a large population with a mean of and a standard deviation

of , then the standard error of the sample mean is inversely proportional to: a. b. c. n d. e. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 69. When drawing all possible simple random samples of a given size n from a population, many different

values of a sample statistic might occur. A listing of all these possible values, along with the associated probabilities of their occurrence, is called the statistic's: a. finite population correction factor b. probability density function c. sampling distribution d. standard normal deviate e. standard error of the sample mean

Chapter 07 - Sampling Distributions ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 70. Given a sampling distribution of the sample mean that is normally distributed and has a mean of 30 and a

standard deviation of 8, a sample mean of 40 corresponds to: a. a z-value of -1.25 b. a z-value of +1.25 c. a z-value of +2.25 d. a sample size of 120 e. a sample size of 300 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 71. Which of the following correctly describes the central limit theorem with respect to ? a. If random samples of n observations are drawn from a nonnormal population with finite mean m and

standard deviation s, then, when n is small enough, the sampling distribution of the sample mean x is approximately normally distributed, with mean μ and standard deviation

b. If random samples of n observations are drawn from a nonnormal population with finite mean m and

standard deviation s, then, when n is large, the sampling distribution of the sample mean x is approximately skewed right, with mean μ and standard deviation

c. If random samples of n observations are drawn from a nonnormal population with finite mean m and

standard deviation s, then, when n is large, the sampling distribution of the sample mean x is approximately skewed left, with mean μ and standard deviation

d. If random samples of n observations are drawn from a nonnormal population with finite mean m and

standard deviation s, then, when n is large, the sampling distribution of the sample mean x is approximately normally distributed, with mean μ and standard deviation

e. If random samples of n observations are drawn from a nonnormal population with finite mean m and

standard deviation s, then, when n is large, the sampling distribution of the sample mean x is approximately normally distributed, with mean μ and standard deviation ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False

Chapter 07 - Sampling Distributions DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/15/2019 3:01 AM 72. Given a population variance of

= 36 and a sample size of n = 9, these imply a standard deviation of the sampling distribution of the sample mean, , of: a. 4 b. 2 c. 1/4 d. 1/2 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 73. Given N = 1,000, n = 30, and

= 6, the standard error of the sample mean, SE

, approximately equals:

a. 009 b. 5 c. 5.5 d. 1.095 e. 33.33 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/1/2019 12:15 PM 74. When a sample is selected at random from a population, the sample mean will likely be: a. larger than the population mean b. smaller than the population mean c. different from the population mean d. equal to the population mean e. larger or equal to the population mean ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/15/2019 3:05 AM

Chapter 07 - Sampling Distributions 75. A numerical descriptive measure calculated from the sample is called: a. a parameter b. a statistic c. a population d. a sampling distribution e. an estimator ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 76. A numerical descriptive measure calculated from the entire population is called: a. a parameter b. a statistic c. a sample d. a sampling distribution e. an estimator ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 77. If the monthly rent of all one-bedroom apartments in a small town are known to be normally distributed with

a mean equal to $175 a month and standard deviation of $35, which of the following would be the highest individual rent that you might expect to find? a. about $195 b. about $210 c. about $245 d. about $280 e. More information is needed to answer the question. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 78. The dean of admissions in a large university has determined that the scores of the freshman class in a

Chapter 07 - Sampling Distributions

mathematics test are normally distributed with a mean of 82 and a standard deviation of 8. Based on this information, what is the mean of the sampling distribution of the sample mean if a sample of 64 students is selected at random from the entire freshman class? a. between 74 and 90 b. between 78 and 86 c. 64 d. 70 e. 82 ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 79. The dean of admissions in a large university has determined that the scores of the freshman class in a

mathematics test are normally distributed with a mean of 82 and a standard deviation of 8. Based on this information, what is the standard deviation of the sampling distribution of the sample mean if a sample of 64 students is selected at random from the entire freshman class? a. 10.25 b. 8.00 c. 2.50 d. 1.00 e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 80. The dean of admissions in a large university has determined that the scores of the freshman class in a

mathematics test are normally distributed with a mean of 82 and a standard deviation of 8. Based on this information, what is the probability that the mean score of a sample of 64 students is at least 80? a. 0987 b. 4772 c. 5987 d. 7885 e. 9772 ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False

Chapter 07 - Sampling Distributions DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 81. The usable lifetime of a particular type of battery is normally distributed with a mean of 1100 days and a

standard deviation of 80 days. The manufacturer randomly selects 400 batteries of this type and ships them to K-Mart. What is the mean of the sampling distribution of ?

What is the standard deviation?

What is the probability the average usable lifetime of these 400 batteries is between 1097 and 1104 days?

ANSWER: 1100; 4; 0.6147 POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/15/2019 3:22 AM 82. The weight of baggage checked by airline passengers is a random variable with a mean of 50 pounds and a

standard deviation of 30 pounds. The total baggage limit for 100 randomly selected passengers is 5750 pounds. What is the mean of the sampling distribution of the sum of the sample measurements?

What is the standard deviation of the sampling distribution of the sum of the sample measurements?

What is the approximate probability the baggage limit will be exceeded?

ANSWER:

5000; 300; 0.0662

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM

Chapter 07 - Sampling Distributions DATE MODIFIED:

4/15/2019 3:40 AM

83. The time necessary to complete an examination has a mean of 45 minutes and a standard deviation of 4

minutes. The average time necessary for 64 randomly selected students is computed. What is the mean of the sampling distribution of ?

What is the standard deviation of the sampling distribution of ?

Can we say that the sampling distribution of is approximately normally distributed?

Why?

ANSWER:

45; 0.5; Yes; Because n = 64 > 30, our rule-of-thumb minimum value for large samples, therefore the CLT can be applied to conclude that the sampling distribution of bar x is approximately normally distributed.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/15/2019 3:37 AM 84. The distribution of scores for the third exam in a statistics course has a mean of 74 and a standard deviation

of 15. A random sample of 36 exam papers is selected. What is the probability that the sample mean is higher than 77?

ANSWER:

0.1151

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 85. It is known that the birth weight of newborn babies in the U.S. has a mean of 7 pounds with a standard

Chapter 07 - Sampling Distributions

deviation of 1.6 pounds. Suppose we randomly sample 64 birth certificates from the State Health Department, and record the birth weights of these babies. Find the mean of the sampling distribution of .

Find the standard deviation.

What is the probability the sample mean birth weight as recorded on the birth certificates will be less than 6.85 pounds?

ANSWER:

7; 0.2; 0.2266

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 86. In a particular large school system, the average IQ of elementary school children is 105 and the standard

deviation is 15. A sample of 81 children is randomly selected from elementary schools within the system. Find the mean of the sampling distribution of .

Find the standard deviation.

What is the probability that the average IQ of this sample is below 108?

ANSWER:

105; 1.667; 0.9641

POINTS: QUESTION TYPE: HAS VARIABLES:

1 Subjective Short Answer False

Chapter 07 - Sampling Distributions STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 87. An auditor is going to sample 64 charge accounts from the many active accounts at a large department store.

Suppose the average balance owed among all the store's accounts is $75 with a standard deviation of $100. Find the mean of the sampling distribution of .

Find the standard deviation.

What is the probability the sample mean of the balances owed among the 64 accounts sampled by the auditor is below $70?

ANSWER:

75; 12.5; 0.3446

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 88. Graduate students applying for entrance to many universities must take a Miller Analogies Test. It is known

the test scores have a mean of 75 and a variance of 16. This year, one hundred students applied for entrance into graduate school in physics. Find the mean of the sampling distribution of .

Find the standard deviation.

Find the probability that the average score of this group of students is higher than 76.

Chapter 07 - Sampling Distributions ANSWER:

75; 0.4; 0.0062

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 89. In a learning experiment, untrained mice are placed in a maze and the time required for each mouse to exit

the maze is recorded. The average time for untrained mice to exit the maze is = 50 seconds and the standard deviation of their times is = 16 seconds. Suppose that 64 randomly selected untrained mice are placed in the maze and the time necessary to exit the maze is recorded for each. Find the mean of the sampling distribution of .

Find the standard deviation.

What is the probability that the sample mean differs from the population mean by more than 3?

ANSWER:

50; 2.0; 0.1336

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/15/2019 3:38 AM 90. The amount of money spent on food per week by an American family is known to have a mean of $92 and a

standard deviation of $9. Suppose a random sample of 81 families is taken and their sample mean food expenditure is calculated. Find the mean of the sampling distribution of .

Find the standard deviation.

Chapter 07 - Sampling Distributions

Find the probability that the sample mean does not exceed $90.40.

ANSWER:

92; 1; 0.0548

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 91. Suppose the average mileage rating (in miles per gallon) of a particular model car is 28 mpg with a standard

deviation of 8 mpg. A random sample of 64 cars of this model is selected. Find the mean of the sampling distribution.

Find the standard deviation.

What is the probability that the sample mean exceeds 30 mpg?

ANSWER:

28; 1; 0.0228

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 92. The mean lifetime of a fluorescent light bulb is 1570 hours with a standard deviation of 200 hours. Suppose

we take a sample of 100 bulbs, test them, and calculate the sample mean. Find the mean of the sampling distribution.

Find the standard deviation.

Chapter 07 - Sampling Distributions

What is the probability the sample mean exceeds 1560 hours?

ANSWER:

1570; 20; 0.6915

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/15/2019 3:39 AM 93. The amount of time to complete a particular exam is believed to have a mean of 52 minutes and a standard

deviation of 4.8 minutes. A sample of 36 students was selected and their times to finish the exam recorded. Is the sampling distribution of the sample mean approximately normal?

What is the mean?

What is the standard deviation?

What is the probability this sample produces an average of less than 50 minutes?

If the sample mean is actually 50 minutes, is it likely that = 52?

Explain.

ANSWER:

Yes; 52; 0.80; 0.0062; No; 50 minutes is more than 2 standard deviations from the mean

Chapter 07 - Sampling Distributions POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 94. The distribution of the amount spent for childcare in a Midwestern city has a mean of $675 and a standard

deviation of $80. A random sample of 64 families paying for childcare is selected. Is the sampling distribution of the sample mean approximately normal?

What is the mean?

What is the standard deviation?

Find the probability that the sample mean is between $645 and $700.

Find the probability that the sample mean is less than $700.

ANSWER:

Yes; 675; 10; 0.9925; 0.9938

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/15/2019 3:57 AM 95. The distribution of heights of adult males has a mean of 69 inches and a standard deviation of 4 inches. A

random sample of 36 adult males is selected. Is the sampling distribution of the sample mean approximately normal?

What is the mean?

Chapter 07 - Sampling Distributions

What is the standard deviation?

Find the probability that the average height will be more than 70 inches.

Find the probability that the average height will be between 67.4 inches and 70.5 inches, inclusively.

ANSWER:

yes; 69; 0.667; 0.0668; 0.9796

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/15/2019 3:52 AM 96. The distribution of the time that a battery pack for a laptop computer can function before requiring

recharging is normal with a mean of 6 hours and standard deviation of 1.8 hours. A random sample of 25 laptops with this type of battery pack is selected and tested. What is the probability that the mean time until recharging is necessary is at least 7 hours?

ANSWER:

0.0027

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 97. Random samples of size n were selected from populations with the means and variances given here. Find the

mean and standard deviation of the sampling distribution of the sample mean in each case: a. n = 36, = 12,

Mean:

SD:

Chapter 07 - Sampling Distributions b. n = 100, = 15,

Mean:

SD: c. n = 8, = 100,

Mean:

SD: ANSWER:

12; 0.5; 15; 0.2; 100; 0.35

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 98. Suppose a random sample of 25 students is selected from a community college where the scores in the final

exam (out of 125 points) are normally distributed, with mean equal to 112 and standard deviation equal to 12. What is the mean of the sampling distribution of the sample mean ?

What is the standard deviation?

Find the probability that exceeds 116.

Find the probability that the sample mean deviates from the population mean = 112 by no more than 4.

ANSWER:

112; 2.4; 0.0478; 0.9044

POINTS: QUESTION TYPE:

1 Subjective Short Answer

Chapter 07 - Sampling Distributions HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 99. Suppose that college faculty with the rank of professor at 4-year institutions earn an average of $72,500 per

year with a standard deviation of $4500. In an attempt to verify this salary level, a random sample of 60 professors was selected from a personnel database for all 4-year institutions in the United States. Is the sampling distribution of the sample mean approximately normal?

What is the mean?

What is the standard deviation?

Within what limits would you expect the sample average to be, with probability 0.95? Lower - $ Upper - $ Calculate the probability that the sample mean is greater than $75,000.

If your random sample actually produced a sample mean of $75,000, would you consider this unusual?

What conclusion might you draw?

ANSWER:

Yes; 72,500; 580.9475; 71,338.105; 73,661.895; 0; Yes; You have observed a very unlikely occurrence, assuming that mu = $72,500. Perhaps your sample was not a random sample, or perhaps the average salary of $72,500 is no longer correct.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/15/2019 4:00 AM

Chapter 07 - Sampling Distributions 100. The total daily sales, x, in the deli section of Carter, a local market in Big Rapids, is the sum of the sales

generated by a fixed number of customers who make purchases on a given day. Is the sampling distribution of the total daily sales approximately normal?

For this particular market, the average sale per customer in the deli section is $10.50 with = $2.50. If 30 customers make deli purchases on a given day, give the mean and standard deviation of the probability distribution of the total sales, x. What is the mean?

What is the standard deviation?

ANSWER:

Yes; 315; 13.693

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 101. An accountant reviewed a firm's billing for an entire year and computed an average bill of $125, with a

standard deviation of $15. The firm's comptroller claims that a sample of 50 bills would have saved a lot of work and achieved the same result. Is the sampling distribution of the sample mean approximately normal?

What is the mean?

What is the standard deviation?

Chapter 07 - Sampling Distributions

Is the comptroller's claim valid?

Explain.

ANSWER:

Yes; 125; 2.12; Yes; In this case, 68.22% of all possible sample means would have been between $122.88 and $127.12. Also, 95.44% of all sample means would have been between $120.76 and $129.24. The comptroller has a point.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 102. As the sample size increases, the standard error of the sample proportion decreases. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 103. The mean of the sampling distribution of the sample proportion when n = 100 and p = 0.5 is 5.0. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 104. The standard error of the sampling distribution of the sample proportion when n = 100 and p = 0.15 is

0.001275. a. True b. False ANSWER:

False

Chapter 07 - Sampling Distributions POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 105. Recall the rule of thumb used to indicate when the normal distribution is a good approximation of the

sampling distribution for the sample proportion . For the combination n = 25; p = 0.05, the rule is satisfied. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 106. As a general rule, the normal distribution is used to approximate the sampling distribution of the sample

proportion only if the sample size n is greater than or equal to 30. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 107. The expression SE ( ) represents the standard error sampling distribution of the sample proportion, . a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 108. The expression SE ( ) represents the standard deviation of the sampling distribution of the sample

proportion, . a. True b. False ANSWER: POINTS:

True 1

Chapter 07 - Sampling Distributions QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 109. Standard error of the sample proportion is another term for the variance of the sampling distribution of the

sample proportion . a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 110. The Central Limit Theorem applies to the sampling distribution of sample proportion but not for the

sampling distribution of sample mean . a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 111. Suppose that 56% of all registered voters in Michigan are supporting John Kerry for president. A sample of

1500 voters is selected at random from Michigan. Based on the concept of sampling distribution of sample proportion , it can be assumed that = .56. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 112. The standard error of the sampling distribution of sample proportion, SE ( ), depends on the value of the

population proportion p, and the closer the value of p to .50, the larger SE ( ) will be for a given sample size n. a. True b. False ANSWER:

True

Chapter 07 - Sampling Distributions POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 113. The sampling distribution of the sample proportion can be approximated by a normal distribution as long

as the population proportion p is very close to .50. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 114. On a particular freeway in Michigan, it is reported that the proportion of cars that exceed the speed limit is

0.15. Given this information, the probability that a sample of 250 cars will have a sample proportion below 0.12 is approximately .0918. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 115. Suppose an actual census showed that 20% of the households in Michigan have incomes in excess of

$60,000. Assume that a random sample of 500 households in Michigan is taken. Then, the standard error of the sampling distribution of sample proportion of households who have incomes in excess of $60,000 will be: a. 0.0179 b. 0.0003 c. 0.1600 d. 0.0256 e. 0.1482 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM

Chapter 07 - Sampling Distributions 116. As a general rule, the normal distribution provides a good approximation to the sampling distribution of the

sample proportion only if: a. the sample size n is greater than 30 b. the sample size n is greater than 100 c. the population proportion p is greater than 0.50 d. the underlying population has a small standard deviation and n is large e. np and n(1-p) are both greater than 5 ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 117. If the standard error of the sampling distribution of the sample proportion is 0.02049 for samples of size

500, then the population proportion must be either: a. 0.2 or 0.8 b. 0.5 or 0.5 c. 0.3 or 0.7 d. 0.6 or 0.4 e. 0.2 or 0.5 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 118. Which of the following statement is true? a. The mean of all possible sample proportions and the expected value of the sampling distribution of

are different. b. The standard deviation of the sampling distribution of the proportion is denoted by x ( ). c. The standard deviation of the sampling distribution of the proportion is denoted by ( ). d. The mean of all possible sample proportions and the expected value of the sampling distribution of are the same and the standard deviation of the sampling distribution of the proportion is denoted by SE ( ). e. The mean of all possible sample proportions and the expected value of the sampling distribution of are the same and the standard deviation of the sampling distribution of the proportion is denoted by ( ). ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice

Chapter 07 - Sampling Distributions HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/15/2019 4:07 AM 119. Given a population proportion of p = .8 and a sample size of n = 100, these imply a standard deviation of

the sampling distribution of the sample proportion of: a. .0258 b. .0355 c. .0400 d. .0538 e. none of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 120. Which of the following statements is false regarding the Central Limit Theorem (CLT) of the sample

proportion ? a. CLT indicates that the mean of the sampling distribution of will be equal to the population proportion p. b. CLT indicates that the sampling distribution of can be approximated by a normal distribution if np > 5 and nq > 5. c. CLT is applied regardless of the sample size n and the population proportion p. d. CLT is applied to non-normal populations. e. CLT indicates that the mean of the sampling distribution of will be equal to the population proportion p and CLT indicates that the sampling distribution of can be approximated by a normal distribution if np > 5 and nq > 5. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 121. Which of the following statements is true regarding the sampling distribution of sample proportion ? a. The mean of the sampling distribution will equal the population proportion p. b. The sampling distribution will be approximately normal provided that np > 5 and nq > 5. c. An increase in the sample size n will result in a decrease in the standard error of . d. All of these. e. None of these. ANSWER: d

Chapter 07 - Sampling Distributions POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 122. In a recent study, it was reported that the proportion of employees who miss work on Fridays is 0.15, and

that the standard deviation of the sampling distribution of sample proportion is 0.025. However, the report did not indicate what the sample size n was. What was it? a. 204 b. 26 c. 108 d. 58 e. More information needed to determine the value of n. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 123. A statistics professor has stated that 90% of his students pass the class. To check this claim, a random

sample of 150 students who have taken the class indicated that 129 passed the class. If the professor's claim is correct, what is the probability that 129 or fewer will pass the class this semester? a. 9484 b. 0516 c. 5516 d. 4484 e. 1624 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/15/2019 4:41 AM 124. Completely describe the distribution of the sample proportion for samples of size n = 500 from a

population with p = 0.4. Is the sampling distribution of the sample proportion approximately normal?

Chapter 07 - Sampling Distributions

What is the mean?

What is the standard deviation?

ANSWER:

Yes; 0.4; 0.0219

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 125. A southern state has an unemployment rate of 6%. The state conducts monthly surveys in order to track the

unemployment rate. In a recent month, a random sample of 700 people showed that 35 were unemployed. If the true unemployment rate is 6%, describe the sampling distribution of . Is the sampling distribution of the sample proportion approximately normal?

What is the mean?

What is the standard deviation?

Find the probability that the sample unemployment rate is at most 5%.

Assume the population proportion, p, is unknown. Describe the sampling distribution of based on the most recent sample. Is the sampling distribution of the sample proportion approximately normal?

What is the mean?

Chapter 07 - Sampling Distributions

What is the standard deviation?

Based on the most recent sample, find the probability that the sample proportion will lie within 0.005 of the true proportion p of people who are unemployed.

ANSWER:

Yes; 0.06; 0.009; 0.1335; Yes; 0.05; 0.008; 0.4714

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 126. Suppose public opinion is split 65% against and 35% for increasing taxes to help balance the federal

budget. 500 people from the population are selected randomly and interviewed. Is the sampling distribution of the sample proportion of people who are in favor of increasing taxes to help balance the federal budget approximately normal?

What is the mean?

What is the standard deviation?

What is the probability the proportion favoring a tax increase is more than 30%?

ANSWER:

Yes; 0.35; 0.02133; 0.9904

POINTS:

Chapter 07 - Sampling Distributions QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 127. A recent nationwide survey by the American Cancer Society found the percentage of women who smoke

has increased to 30%. That seems a little low for your state, so you sample 500 women from your state and find 180 of them smoke. Find the sample proportion of women who smoke in your state.

Describe sampling distribution of ; the proportion of women who smoke. Is the sampling distribution approximately normal?

What is the mean?

What is the standard deviation?

What is the probability that at least 36% of women in your state are smokers if the true population proportion p = 0.30?

Does your answer to the previous question cast doubt on the American Cancer Society's claim?

ANSWER:

0.36; Yes; 0.30; 0.0205; 0.0017; Yes

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic

Chapter 07 - Sampling Distributions DATE CREATED: DATE MODIFIED:

2/4/2019 9:15 AM 2/4/2019 9:15 AM

128. Suppose a sample of 120 items is drawn from a population of manufactured products and the number of

defective items is recorded. Prior experience has shown that the proportion of defectives is 0.05. Is the sampling distribution of the proportion of defectives approximately normal?

What is the mean?

What is the standard deviation?

What is the probability that the sample proportion is less than 0.10?

How would the sampling distribution of the sample proportion change if the sample size were raised to 200?

ANSWER:

Yes; 0.05; 0.0199; 0.994; The standard deviation (or standard error) would decrease

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 129. A machine which manufactures a part for a car engine was observed over a period of time before a random

sample of 300 parts was selected from those produced by this machine. Out of the 300 parts, 15 were defective. Find the proportion of defective parts in the sample.

Is the sampling distribution of the proportion of defectives approximately normal?

Chapter 07 - Sampling Distributions

What is the mean?

What is the standard deviation?

What is the probability that the sample proportion will lie within 0.02 of the true population proportion of defective parts?

ANSWER:

0.05; Yes; 0.05; 0.0126; 0.8882

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/16/2019 3:05 AM 130. A candy bar company is interested in reducing the percent defective candy bars made, where a defective

candy bar has too few almonds by weight. The company randomly samples 100 candy bars a day for 5 days and finds the percent defective to be 0.0200, 0.0125, 0.0225, 0.0100, and 0.0150. The company wants to construct a control chart for the proportion defective in samples of size n = 100. Estimate the process fraction defective p.

Estimate the standard deviation of the sample proportions.

What are the control limits?

UCL =

LCL = How are these control limits used?

Chapter 07 - Sampling Distributions ANSWER:

0.016; 0.0125; 0.0535; 0.00; When the sample percentage defective exceeds 5.35%, the process needs to be adjusted

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 131. A student government representative at a local university claims that 60% of the undergraduate students

favor a move to Division I in college football. A random sample of 250 undergraduate students is selected. Is the sampling distribution of the sample proportion approximately normal?

What is the mean?

What is the standard deviation?

Find the probability that the sample proportion exceeds 0.65.

ANSWER:

Yes; 0.60; 0.0310; 0.0537

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/16/2019 3:07 AM 132. A TV pollster believed that 70% of all TV households would be tuned in to Game 6 of the 1997 NBA

Championship series between the Chicago Bulls and the Utah Jazz. A random sample of 500 TV households is selected. Is the sampling distribution of the sample proportion approximately normal?

What is the mean?

Chapter 07 - Sampling Distributions

What is the standard deviation?

Find the probability that the sample proportion on will be between 0.65 and 0.75.

ANSWER:

Yes; .70; 0.0205; 0.9854

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/16/2019 3:08 AM 133. A well-known juice manufacturer claims that its citrus punch contains 15% real orange juice. A random

sample of 150 cans of the citrus punch is selected and analyzed for content composition. Is the sampling distribution of the sample proportion approximately normal?

What is the mean?

What is the standard deviation?

Find the probability that the sample proportion will be less than 0.10.

Would a value of = 0.25 be considered unusual?

Explain.

ANSWER:

Yes; 0.15; 0.0292; 0.0436; Yes; Because the corresponding z-score = 3.42 indicates that the value of p hat = 0.25 is 3.42 standard deviations above the mean.

POINTS: QUESTION TYPE: HAS VARIABLES:

1 Subjective Short Answer False

Chapter 07 - Sampling Distributions STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 4/16/2019 3:11 AM 134. The proportion of individuals with an Rh-positive blood type is 88%. You have a random sample of n =

500 individuals. What is the mean of , the sample proportion with Rh-positive blood type?

What is the standard deviation?

Is the distribution approximately normal?

What is the probability that the sample proportion exceeds 85%.

What is the probability that the sample proportion lies between 86% and 91%?

99% of the time, the sample proportion would lie between what two limits? Lower Limit =

Upper Limit = ANSWER:

0.88; 0.0145; Yes; 0.9808; 0.897; 0.8462; 0.9138

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM

Chapter 07 - Sampling Distributions 135. Assume that the proportion of defective items in a sample of 400 items is 0.20.

Is the normal approximation to the sampling distribution of appropriate in this situation?

Find the probability that is greater than 0.23.

Find the probability that lies between 0.16 and 0.24.

ANSWER:

Yes; 0.0668; 0.9544

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 136. According to one study, 50% of Americans admit to overeating sweet foods when stressed. Suppose that

the 50% figure is correct and that a random sample of n = 100 Americans is selected. Does the distribution of , the sample proportion of Americans who relieve stress by overeating sweet foods, have an approximately normal distribution?

What is the mean?

What is the standard deviation?

What is the probability that the sample proportion, , exceeds 0.54?

Chapter 07 - Sampling Distributions

What is the probability that lies within the interval 0.39 to 0.59?

Would it be unusual if the sample proportion were as small as 34%?

ANSWER:

Yes; 0.5; 0.05; 0.2119; 0.9502; Yes

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 137. A production process produces 10 percent defective items.

Describe the sampling distribution of the proportion of defectives for a simple random sample of n = 50. Is the distribution approximately normal?

What is the mean?

What is the standard deviation?

What is the likelihood of encountering a sample proportion within 0.03 of the population proportion?

If the production process is shut down whenever a sample proportion of defectives exceeds 0.05, what is the likelihood of this happening?

ANSWER:

Yes; 0.10; 0.0424; 0.5222; 0.8810

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic

Chapter 07 - Sampling Distributions DATE CREATED: DATE MODIFIED:

2/4/2019 9:15 AM 4/16/2019 3:18 AM

138. The cause of a change in a process variable being monitored is regarded as random variation if it can be

found and corrected. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 139. Small haphazard changes in a process variable due to alteration in the production environment that is not

controllable are said to be assignable causes. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 140. If the variation in a process variable is solely random, the process is said to be in control. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 141. The first objective in statistical process control is to eliminate assignable causes of variation in the process

variable and then get the process in control. The next step is to reduce variation and get the measurements on the process variable within specification limits, the limits within which the measurements on usable items or services must fall. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False

Chapter 07 - Sampling Distributions DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 142. Once a process is in control and is producing a satisfactory product, the process variables are monitored by

use of control charts. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 143. Statistical process control (SPC) methodology was developed to monitor, control, and improve products

and services. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 144. If a process is in control, we expect all the data values to fall within one standard deviation of the mean. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:15 AM DATE MODIFIED: 2/4/2019 9:15 AM 145. If a process is in control, we expect all the data values to fall within two standard deviations of the mean. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:16 AM DATE MODIFIED: 2/4/2019 9:16 AM

Chapter 07 - Sampling Distributions 146. If a process is in control, we expect all the data values to fall within three standard deviations of the mean. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:16 AM DATE MODIFIED: 2/4/2019 9:16 AM 147. Random variation in a process can be eliminated. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:16 AM DATE MODIFIED: 2/4/2019 9:16 AM 148. Random cause variation refers to variation n, the output of a process that is unexpected and has an

assignable cause. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:16 AM DATE MODIFIED: 2/4/2019 9:16 AM 149. Assignable cause variation refers to variation in the output of a process that is naturally occurring,

expected, and that may be the result of random causes. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:16 AM DATE MODIFIED: 2/4/2019 9:16 AM 150. Process control charts, such as the and p-charts, are used to provide signals to indicate when the output of

a process is out of control.

Chapter 07 - Sampling Distributions a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:16 AM DATE MODIFIED: 2/4/2019 9:16 AM 151. If a process is in control and is producing a satisfactory product, the process variables can be monitored

with control charts. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:16 AM DATE MODIFIED: 4/16/2019 3:34 AM 152. In control process is typically defined as a process in which all output is operating within 3 standard

deviation of the centerline of the process. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:16 AM DATE MODIFIED: 2/4/2019 9:16 AM 153. In most processes, the process control limits are set to correspond with the specification limits on the

process. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:16 AM DATE MODIFIED: 2/4/2019 9:16 AM 154. For a control chart, the lower and upper control limits are usually set at: a. one standard deviation from the centerline

Chapter 07 - Sampling Distributions b. two standard deviations from the centerline c. three standard deviations from the centerline d. four standard deviations from the centerline e. five standard deviations from the centerline ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:16 AM DATE MODIFIED: 2/4/2019 9:16 AM 155. Twenty five samples of size 1000 each were drawn from a manufacturing process and the number of

defectives in each sample was counted. The average sample proportion was 0.05. The upper control limit for the p chart is: a. 0.0475 b. 0.0206 c. 0.0293 d. 0.0707 e. 0.0635 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:16 AM DATE MODIFIED: 2/4/2019 9:16 AM 156. The mean of the sample means and the standard deviation of 50 samples of size 5 taken from a production

process under control are found to be 300 and 25, respectively. The lower control limit for the chart is located at: a. 333.54 b. 289.39 c. 310.61 d. 266.46 e. 342.88 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:16 AM DATE MODIFIED: 4/16/2019 3:44 AM 157. Fifty samples of size 500 were drawn from a manufacturing process and the number of defectives in each

sample was counted. The average of the sample proportion was 0.032. The centerline for the p chart is:

Chapter 07 - Sampling Distributions a. 0.032 b. 16.0 c. 0.512 d. 0.968 e. 4.2 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:16 AM DATE MODIFIED: 2/4/2019 9:16 AM 158. Sixty samples of size 600 each were drawn from a manufacturing process and the number of defectives in

each sample was counted. The average sample proportion was 0.04. The lower control limit for the p chart is: a. 0.008 b. 0.016 c. 0.064 d. 0.048 e. 0.032 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:16 AM DATE MODIFIED: 2/4/2019 9:16 AM 159. Small changes due to alteration in the production environment, that is not controllable is regarded as: a. random variation b. special cause variation c. common cause variation d. within-group variation e. none of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:16 AM DATE MODIFIED: 4/16/2019 4:05 AM 160. Every control chart has: a. the centerline b. the upper control limit c. the lower control limit

Chapter 07 - Sampling Distributions d. all of these e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:16 AM DATE MODIFIED: 4/16/2019 4:07 AM 161. A candy bar factory is pouring chocolate into molds to cool. The finished bars are sold as 1.25 ounce bars.

The company will lose money if the molds are over-filled. If the molds are under-filled, the weight of the candy bars will be less than the wrapper label says, and the Food and Drug Administration will fine the company for misrepresenting the size of its product. The company wants to create an chart to monitor the weight of the candy bars. Suppose there are 5 samples of size 30 each taken, and their sample means are 1.27, 1.22, 1.26, 1.23, and 1.26 ounces. What is the centerline value?

The calculated value of s, the sample standard deviation of all nk = (30)(5) = 150 observations, is 0.12 ounces. What is the standard error of the mean of 30 observations?

What are the control limits?

UCL =

LCL = How is the chart used in this situation?

ANSWER:

1.248; 0.0219; 1.3137; 1.1823; Samples are selected and their sample mean calculated. The company readjusts its candy mold-filling machine whenever a sample mean falls outside the control limits.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic

Chapter 07 - Sampling Distributions DATE CREATED: DATE MODIFIED:

2/4/2019 9:16 AM 2/4/2019 9:16 AM

162. Samples of n = 100 items were selected hourly over a 100-hour period, and the sample proportion of

defectives was calculated each hour. The mean of the 100 sample proportions was 0.042. Calculate the upper and lower control limits for a p chart.

UCL =

LCL = Explain how to construct a p chart for the process and how it can be used.

ANSWER:

0.1022; 0; The control chart is constructed by plotting three horizontal lines, one located at the upper control limit 0.1022, one at the centerline, and one at the lower control limit 0. Values are plotted, and should remain within the control limits. If not, the process should be checked.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:16 AM DATE MODIFIED: 2/4/2019 9:16 AM 163. A producer of brass rivets randomly samples 500 rivets each hour and calculates the proportion of

defectives in the sample. The mean sample proportion calculated from 250 samples was equal to 0.025. Calculate the upper and lower control limits for a control chart for the proportion of defectives in samples of 500 rivets.

UCL =

LCL = ANSWER:

0.046; 0.004

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:16 AM DATE MODIFIED: 2/4/2019 9:16 AM

Chapter 07 - Sampling Distributions

Chapter 08 - Large-Sample Estimation 1. An interval estimate is an interval that provides an upper and lower bound for a specific population parameter

whose value is unknown. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM 2. A statistic is said to be unbiased if its sampling distribution has the smallest standard error. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM 3. A point estimate is a single number that is used as an estimate of a population parameter or population

characteristic. It is usually derived from a random sample from the population of interest. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM 4. The maximum distance between an estimate and the true value of the parameter is called the margin of error. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 4/2/2019 6:56 AM 5. An unbiased estimator of a population parameter is an estimator whose variance is the same as the actual

value of the population variance. a. True

Chapter 08 - Large-Sample Estimation b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM 6. The sample standard deviation s is an unbiased estimator of the population standard deviation a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM

7. An estimator is a random variable calculated from a random sample that provides either a point estimate or an

interval estimate for some population parameter. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM 8. The error of estimation is the distance between an estimate and the true value of the estimated parameter. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 4/2/2019 7:05 AM 9. An estimator is unbiased if the mean of its sampling distribution is equal to the true value of the population

parameter being estimated. a. True b. False ANSWER:

True

Chapter 08 - Large-Sample Estimation POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 4/2/2019 7:04 AM 10. The process of inferring the values of unknown population parameters from those of known sample statistics

is called estimation. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM 11. A point estimate is an estimate of a population parameter, expressed as a single numerical value. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM 12. A sample statistic such that the mean of all its possible values differs from the population parameter the

statistic seeks to estimate is a biased estimator. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM 13. A sample statistic such that the mean of all its possible values equals the population parameter the statistic

seeks to estimate is an unbiased estimator. a. True b. False ANSWER: POINTS:

True 1

Chapter 08 - Large-Sample Estimation QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM 14. The margin of error equals the sum of an estimator's squared bias and its variance. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 4/2/2019 7:08 AM 15. The error of estimation is the difference between a statistic computed from a sample and the corresponding

parameter computed from the population. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM 16. If a store manager is interested in estimating the mean amount spent per customer per visit at her store, the

sample mean would be the appropriate point estimate. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 4/2/2019 7:17 AM 17. If John Kerry's campaign manager is interested in estimating the proportion of registered voters who will

support Kerry on November 2nd, 2004, the sample proportion would be the appropriate point estimate. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False

Chapter 08 - Large-Sample Estimation HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 4/2/2019 7:20 AM 18. If a store manager has recently stated that she estimates the mean amount spent per customer per visit to be

between $38.75 and $72.23, the numbers $38.75 and $72.23 are considered point estimates for the true population mean. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM 19. A point estimate of a population parameter will likely be different from the corresponding population value

due to the fact that point estimates are subject to sampling error. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM 20. The concept of margin of error applies directly when estimating the population mean , but is not applicable

when estimating the population proportion p. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM 21. Which of the following statements is correct? a. A point estimate is an estimate of the range of a population parameter. b. An interval estimate is an estimate of the range for a sample statistic. c. A point estimate is a single value estimate of the value of a population parameter. d. An interval estimate is an estimate of the value of a population parameter. e. A point estimate is an estimate of the midpoint of the range for a sample statistic.

Chapter 08 - Large-Sample Estimation ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM 22. An unbiased estimator is: a. any sample statistic used to approximate a population parameter b. a sample statistic, which has an expected value equal to the value of the population parameter c. a sample statistic whose value is usually less than the value of the population parameter d. a sample statistic whose value is usually greater than the value of the population parameter e. any estimator whose standard error is relatively small ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM 23. A point estimate is defined as: a. the average of the sample values b. the average of the population values c. a single value that is the best estimate of an unknown population parameter d. a single value that is the best estimate of an unknown sample statistic e. a single value that is the best estimate of the upper range of a population parameter ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM 24. From a sample of 200 items, 12 items are defective. The point estimate of the population proportion

defective will be: a. 12 b. 0.06 c. 16.67 d. 0.12 e. 1.6 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice

Chapter 08 - Large-Sample Estimation HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM 25. Which of the following is a parameter? a. the sample mean b. the sample standard deviation c. the sample proportion d. all of these e. none of these ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM 26. Estimation is best defined as: a. a process of inferring the values of unknown population parameters from those of known sample

statistics b. a process of inferring the values of unknown samples statistics from those of known population parameters c. any procedure that views the parameter being estimated not as a constant, but, just like the estimator, as a random variable d. a sampling procedure that matches each unit from population A with a "twin" from population B so that any sample observation about a unit in population A automatically yields an associated observation about a unit in population B e. both a process of inferring the values of unknown samples statistics from those of known population parameters and any procedure that views the parameter being estimated not as a constant, but, just like the estimator, as a random variable ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM 27. The type of sample statistic that is used to make inferences about a given type of population parameter is

called: a. the estimator of that parameter b. the confidence level of that parameter c. the confidence interval of that parameter d. the point estimate of that parameter e. the interval estimate of that parameter

Chapter 08 - Large-Sample Estimation ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM 28. A sample statistic such that the mean of all its possible values differs from the population parameter the

statistics seeks to estimate is called: a. an efficient estimator b. an inconsistent estimator c. a biased estimator d. a Bayesian estimator e. a least squares estimator ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM 29. Whenever a sampled population is normally distributed or whenever the conditions of the central limit

theorem are fulfilled, the sample mean,

is:

a. a consistent estimator of the population mean, , because the mean of the sampling distribution of the

sample mean, equals . b. an efficient estimator of the population mean, , because the mean of the sampling distribution of the sample mean equals . c. an unbiased estimator of the population mean, , because the mean of the sampling distribution of the sample mean equals . d. a biased estimator of the population mean, , because the mean of the sampling distribution of the sample proportion equals p. e. an efficient estimator of the population mean, , because the mean of the sampling distribution of the sample proportion equals p. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 4/2/2019 7:29 AM 30. Which of the following statements about the margin of error is false? a. Statisticians routinely construct interval estimates by making their point estimate the interval center

and creating a range of other possible values, known as the margin of error, below and above the

Chapter 08 - Large-Sample Estimation

center. b. The margin of error is a half-width of an interval estimate, equal to the difference between the point estimate on the one hand and either the lower or upper limit of the interval on the other hand. c. The unknown parameter is presumed to lie at the center of the interval that point estimate and margin of error create. d. The margin of error only takes sampling error into account, ignoring all other potential sources of error, such as bias in questions, selection bias, or miscalculations. e. None of these. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM 31. Which of the following statements is true with respect to a point estimate? a. It is subject to sampling error and will almost always be different from the true value of the

population parameter. b. It is a population parameter. c. It is the upper value of an interval estimate. d. Neither it is subject to sampling error and will almost always be different from the true value of the population parameter nor it is a population parameter. e. Both it is subject to sampling error and will almost always be different from the true value of the population parameter and it is a population parameter. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM 32. In order to estimate the average numbers of miles that students who live off-campus commute to classes

every day, the following statistics were given: n = 50, = 5.21, and s = 2.48. The point estimate of the true population mean is: a. 1.96 b. 2.10 c. 5.21 d. 7.07 e. 2.78 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False

Chapter 08 - Large-Sample Estimation DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM 33. The margin of error is: a. the difference between the point estimate and the true value of the population parameter b. the critical value multiplied by the standard error of the estimator c. the smallest possible sampling error d. both the difference between the point estimate and the true value of the population parameter and the

critical value multiplied by the standard error of the estimator e. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 4/2/2019 7:33 AM 34. A random sample of 45 door-to-door encyclopedia salespersons were asked how long on average they were

able to talk to the potential customer. Their answers revealed a mean of 8.5 minutes with a variance of 9 minutes. Give a point estimate in minutes for the average conversation length.

Give the margin of error. Round your answer to two decimal places.

ANSWER:

8.5; 0.88

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 4/2/2019 7:52 AM 35. Twenty retired people living within the Crystal city limits were asked if they would use public transportation

if a system was implemented. Their responses are listed below where Y = Yes and N = No. Use these data to estimate p, the true proportion of all retired people living within the city limits that would use a public transportation system, and find the estimated margin of error. Round your answers to one decimal place. YNNNN NYYYY NNYYY YYYYN

Chapter 08 - Large-Sample Estimation

The point estimate is: The margin of error is: _ ANSWER:

0.6; 0.2

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 4/2/2019 8:18 AM 36. A proportion of a college basketball team's season ticket holders renew their tickets for the next season. Let

p denote the true proportion of ticket holders who buy tickets again for the following season. A random sample of 125 ticket holders revealed 90 people plan on renewing their tickets. Give a point estimate for p and find the estimated margin of error. For the margin of error, round your answer to three decimal places. The point estimate is: The margin of error is: _ ANSWER:

0.72; 0.079

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 4/2/2019 8:20 AM 37. A random sample of n = 1000 observations from a binomial population produced x = 728 successes.

Estimate the binomial proportion p.

Calculate the margin of error. Round your answer to four decimal places.

ANSWER:

0.728; 0.0276

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic 2/4/2019 9:18 AM DATE CREATED: DATE MODIFIED: 4/2/2019 8:21 AM

Chapter 08 - Large-Sample Estimation 38. A random sample of n = 50 observations from a quantitative population produced = 65.4 and s2 = 2.8.

Give the best point estimate for the population mean, .

Calculate the margin of error. Round your answer to four decimal places.

ANSWER:

65.4; 0.4638

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 4/2/2019 8:22 AM 39. Radio and television stations often air controversial issues during broadcast time and ask viewers to indicate

their agreement or disagreement with a given stand on the issue. A poll is conducted by asking those viewers who agree to call a certain 900 telephone number and those who disagree to call a second 900 telephone number. All respondents pay a fee for their calls. Does this polling technique result in a random sample?

Are the results of such a survey valid?

Explain.

ANSWER:

No; No; This method of sampling would not be random, since only interested viewers (those who were adamant in their approval or disapproval) would reply. The results of such a survey will not be valid, and a margin of error would be useless, since its accuracy is based on the assumption that the sample was random.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM

Chapter 08 - Large-Sample Estimation 40. Independent samples of n1 = 400 and n2 = 400 observations were selected from binomial populations 1 and

2, and x1 = 100 and x2 = 127 successes were observed. a. What is the best point estimator for the difference (p1 – p2) in the two binomial proportions?

b. Calculate the approximate standard error for the statistic used in part (a).

c. What is the margin of error for this point estimate?

–0.0675; 0.0318; 0.0623

ANSWER:

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:18 AM DATE MODIFIED: 2/4/2019 9:18 AM 41. As the sample size increases and other factors are the same, the width of a confidence interval for a

population mean tends to decrease. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 42. Suppose a 95% confidence interval for the mean height of a 12-year-old male in the United States is 54 to 65

inches. It can be said that 95% of 12-year-old males in the U.S. have height greater than or equal to 54 inches and less than or equal to 65 inches. a. True b. False ANSWER:

True

POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False

Chapter 08 - Large-Sample Estimation DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 43. If the population variance is increased and other factors are the same, the width of a confidence interval for

the population mean tends to increase. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 44. The sample proportion is an unbiased estimator of the population proportion p. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 45. The confidence coefficient is the probability that a confidence interval will enclose the estimated parameter. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 46. The lower and upper limits of the 68.26% confidence interval for the population mean , given that n = 49;

= 75; and = 7, are 74 and 76, respectively. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM

Chapter 08 - Large-Sample Estimation 47. In the formula:

, the

refers to the area in the lower tail or upper tail of the sampling

distribution of the sample mean. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 48. In order to construct a confidence interval for a population proportion p, the value of p is needed. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/2/2019 8:43 AM 49. When constructing a confidence interval for a population mean , the population standard deviation

equaled 6. The obtained interval was 45.0 1.5. If

equals 12, the confidence interval will be 90 3.

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/2/2019 9:08 AM 50. A 90% confidence interval estimate for a population mean is determined to be 62.8 to 73.4. If the

confidence level is reduced to 80%, the confidence interval for becomes narrower. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 51. When constructing a confidence interval for a population parameter, we generally set the confidence

Chapter 08 - Large-Sample Estimation

coefficient ( ) close to 0 (usually between 0 and 0.05) because it is the probability that the interval does not include the actual value of the population parameter. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 52. Suppose that a 95% confidence interval for the population proportion p is given by

means that we are 95% confident that p takes values between

and

. This notation

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/2/2019 9:07 AM 53. The lower limit of the 90% confidence interval for the population proportion p, given that n = 400; and =

0.10, is 0.1247. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 54. A term confidence level refers to an estimate of a population parameter, expressed as a range of values

within which the unknown but true parameter presumably lies. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/2/2019 9:19 AM

Chapter 08 - Large-Sample Estimation 55. The term confidence interval refers to the range of values among which an unknown population parameter

can presumably be found. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 56. The two limits that define an interval estimate are known as confidence limits. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 57. A confidence interval for the population mean will contain the true value of as long as the point estimate

is within the lower and the upper confidence limits. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 58. A confidence interval for the population proportion p may or may not contain the true value of p. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 59. The wider the confidence interval, the more likely it is that the interval contains the true value of the

population parameter.

Chapter 08 - Large-Sample Estimation a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 60. If a population is right skewed, the point estimate will be pushed to the right of the middle of the confidence

interval estimate. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 61. Based on the formula

we can assume that the point estimate of the population mean will be at the center of the confidence interval estimate. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 62. A 95% confidence interval for the population proportion p is found to be between .214 and .336. Based on

this information, the sample proportion that generated the confidence interval was .122. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 63. A 90% confidence interval for the population mean is found to be between 5.28 and 6.72. Based on this

information, the sample mean that generated the confidence interval was 6.

Chapter 08 - Large-Sample Estimation a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 64. In constructing a confidence interval for a population parameter, such as or p , the margin of error is

directly dependent on the value of the point estimate. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 65. Increasing the confidence coefficient from .90 to .95 and decreasing the sample size from 100 to 50 has

unknown impact on the margin of error. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 66. One way to reduce the margin of error in a confidence interval is to decrease the confidence coefficient. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 67. For a given sample size and given confidence coefficient, the closer the population proportion p to 1.0, the

greater the margin of error will be. a. True

Chapter 08 - Large-Sample Estimation b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 68. A 90% confidence interval for a population mean can be interpreted as follows: a. if we repeatedly draw samples of the same size from the same population, 90% of the values of the

sample means will result in a confidence interval that includes the population mean . b. there is a 90% probability that the population mean will lie between the lower confidence limit (LCL) and the upper confidence limit (UCL). c. we are 90% confident that we have selected a sample whose range of values does not contain the population mean . d. we are 90% confident that 10% the values of the sample means will result in a confidence interval

that includes the population mean . e. 90% of the values of the sample means are equal to the population mean . ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/2/2019 9:26 AM 69. Which of the following statements is false? a. The width of a confidence interval for a population mean narrows when the sample size increases. b. The width of a confidence interval for a population mean narrows when the value of the sample mean

increases. c. The width of a confidence interval for a population mean widens when the confidence level increases. d. Both “The width of a confidence interval for a population mean narrows when the sample size increases” and “The width of a confidence interval for a population mean widens when the confidence level increases.” e. None of these. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/2/2019 9:30 AM

Chapter 08 - Large-Sample Estimation 70. A 99% confidence interval estimate for a population mean is determined to be 85.58 to 96.62. If the

confidence level is reduced to 90%, the confidence interval for : a. becomes wider b. remains the same c. becomes narrower d. becomes wider on the left but remains the same on the right e. does none of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 71. When constructing a confidence interval for a population mean, the population standard deviation

was 8.

The obtained interval was 40.52 3.24. If equals 16, the confidence interval will be: a. 40.52 11.24 b. 48.52 11.24 c. 81.04 11.24 d. 40.52 6.48 e. 81.04 6.48 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/2/2019 9:37 AM 72. When constructing a confidence interval for a population mean, a sample of 40 observations was taken. The

obtained interval was 17.25 2.42. If the sample size is 160 instead of 40, the confidence interval will be: a. 17.25 9.68 b. 17.25 1.21 c. 69.00 9.68 d. 34.50 4.82 e. 69.00 1.21 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/2/2019 9:40 AM

Chapter 08 - Large-Sample Estimation 73. After constructing a confidence interval estimate for a population mean, you believe that the interval is

useless because it is too wide. In order to correct this problem, you need to: a. increase the population size b. increase the sample mean c. increase the confidence coefficient d. increase the sample size e. decrease the sample size ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 74. Which of the following is not a part of the formula for constructing a confidence interval for a population

proportion? a. a point estimate of the population proportion b. the standard error of the sampling distribution of the sample proportion c. the confidence coefficient d. the value of the population proportion e. the standard error of the sampling distribution of the sample proportion and the confidence

coefficient ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/2/2019 9:44 AM 75. The use of the standard normal distribution for constructing confidence interval estimate for the population

proportion p requires: a. and are both greater than 5, where is the sample proportion b. np and n(1 – p) are both greater than 5 c. (p + ) and (p – ) are both greater than 1 d. that the sample size is greater than 5 e. np and n(1 – p) are both greater than 1 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM

Chapter 08 - Large-Sample Estimation 76. The lower limit of a confidence interval at the 95% level of confidence for the population proportion if a

sample of size 100 had 30 successes is: a. 0.3898 b. 0.2102 c. 0.2959 d. 0.3041 e. 0.3126 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 77. Which of the following best defines an interval estimate? a. It is a sampling procedure that matches each unit from population A with a "twin" from population B

so that any sample observation about a unit in population A automatically yields an associated observation about a unit in population B. b. It is an estimate of a population parameter that is expressed as a range of values within which the unknown but true parameter presumably lies. c. It is a sample statistic such that the mean of all its possible values equals the population parameter the statistic seeks to estimate. d. It is the sum of an estimator's squared bias plus its variance. e. It is the sum of an estimator's squared bias plus the population mean . ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 78. When estimating a population mean , where the population standard deviation

is known, we can:

a. define the limits of an interval estimate of as b. define the limits of an interval estimate of as c. choose a smaller z value, construct a narrower confidence interval, and achieve a higher confidence

level d. choose a larger z value, construct a wider confidence interval, and achieve a lower confidence level ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM

Chapter 08 - Large-Sample Estimation 79. The term confidence level refers to: a. the absolute number of interval estimates that can be expected to contain the actual value of the

parameter being estimated when the same procedure of interval construction is used again and again b. the percentage of interval estimates that can be expected to contain the actual value of the parameter being estimated when the same procedure of interval construction is used again and again c. the range of values among which an unknown population parameter can presumably be found d. the sum of an estimator's squared bias plus its variance, which indicates the degree to which it is consistent, efficient, and unbiased e. the percentage of interval estimates that can be expected to contain the actual value of the parameter being estimated when the same procedure of interval construction is used again and again and the range of values among which an unknown population parameter can presumably be found ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 80. A random sample of 400 Michigan State University (MSU) students were surveyed recently to determine an

estimate for the proportion of all MSU students who had attended at least three football games. The estimate revealed that between .372 and .458 of all MSU students attended. Given this information, we can determine that the confidence coefficient was approximately: a. 99 b. 95 c. 92 d. 90 e. 88 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 81. A 95% confidence interval for the population proportion of professional tennis players who earn more than 2

million dollars a year is found to be between .82 and .88. Given this information, the sample size that was used was approximately: a. 545 b. 382 c. 233 d. 387 e. 480 ANSWER:

Chapter 08 - Large-Sample Estimation POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 82. A recent survey indicates that the proportion of season ticket holders for Ferris State University hockey team

that renew their seats is about .80. Using this information, the sample size that is needed to estimate the true proportion that plan to renew their seats using 95% confidence and a margin of error of .025 is about: a. 689 b. 697 c. 810 d. 984 e. 1,179 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 83. The role of the sample mean in a confidence interval estimate for the population mean is to determine: a. the sample size needed b. the confidence coefficient 1 – c. the margin of error in the estimate d. all of these e. none of these ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 84. If the population deviation

is known and we wish to estimate the population mean with 95% confidence, what is the appropriate critical value z to use? a. 1.28 b. 1.645 c. 1.96 d. 2.33 e. 2.58 ANSWER: POINTS:

c 1

Chapter 08 - Large-Sample Estimation QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 85. If the population deviation

is known and we wish to estimate the population mean with 90% confidence, what is the appropriate critical value z to use? a. 1.28 b. 1.645 c. 1.96 d. 2.33 e. 2.58 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 86. A statistician wants to reduce the margin of error associated with a confidence interval for a population

proportion p. He needs to: a. reduce the confidence level 1 – b. decrease the sample size n c. take another sample d. increase the confidence level 1 – e. do none of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/2/2019 9:53 AM 87. A random sample of 45 door-to-door encyclopedia salespersons were asked how long on average they were

able to talk to the potential customer. Their answers revealed a mean of 8.5 minutes with a variance of 9 minutes. Construct a 95% confidence interval for , the time it takes an encyclopedia salesperson to talk to a potential customer. Round your answer to two decimal places.

ANSWER:

(7.62, 9.38)

POINTS: QUESTION TYPE: HAS VARIABLES:

1 Subjective Short Answer False

Chapter 08 - Large-Sample Estimation STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/2/2019 9:57 AM 88. A study conducted by a commuter train transportation authority involved surveying a random sample of 200

passengers. The results show that a customer had to wait on the average 9.3 minutes with a standard deviation of 6.2 minutes to buy his or her ticket. Construct a 95% confidence interval for , the true mean waiting time. Round your answer to two decimal places.

ANSWER:

(8.44, 10.16)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/2/2019 10:04 AM 89. A study conducted by the doctors of a particular hospital involved monitoring a random sample of 75

patients. The results showed it took an average of 3 cc of tranquilizer to put a patient to sleep before surgery with a standard deviation of 0.2 cc. Construct a 95% confidence interval for , the true mean amount of tranquilizer needed to put any patient to sleep. Round your answer to two decimal places.

ANSWER:

(2.95, 3.05)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/2/2019 10:06 AM 90. A random sample of 60 people revealed it took an average of 55 minutes with a standard deviation of 10

minutes for a person to complete a loan application at the bank. Construct a 90% confidence interval for , the true time it takes any person to complete the loan form. Round your answer to two decimal places.

ANSWER:

(52.88, 57.12)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/3/2019 1:18 AM

Chapter 08 - Large-Sample Estimation 91. An auto mechanic knows the average time it takes to replace a bad car radiator is 70 minutes with a standard

deviation of 12 minutes. This average is based on a random sample of 50. Construct a 90% confidence interval for . Round your answer to two decimal places.

ANSWER:

(67.21, 72.79)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/3/2019 1:20 AM 92. A random sample of 80 jars of grape jelly has a mean weight of 20 oz. with a standard deviation of 1.7 oz.

Construct a 99% confidence interval for , the true weight of a jar of jelly. Round your answer to two decimal places.

ANSWER:

(19.51, 20.49)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/3/2019 1:23 AM 93. A study was conducted to see how long Dr. Kennedy's patients had to wait before their appointment. A

random sample of 33 patients showed the average waiting time was 22 minutes with a standard deviation of 16 minutes. Construct a 99% confidence interval for , the true mean waiting time. Round your answer to two decimal places.

ANSWER:

(14.81, 29.19)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/3/2019 1:35 AM 94. A college graduate school president wants to know what proportion of applicants would like to be accepted

into the chemistry department. Of a random sample of 75 applicants, 12 requested the chemistry department. Construct a 95% confidence interval for p, the true proportion of all applicants that prefer chemistry. Round your answer to three decimal places.

Chapter 08 - Large-Sample Estimation

ANSWER:

(0.077, 0.243)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/3/2019 1:42 AM 95. A lawn service owner is testing new weed killers. He discovered that a particular weed killer was effective

89% of time. Suppose that this estimate was based on a random sample of 60 applications. Construct a 90% confidence interval for p, the true proportion of weeds killed by this particular brand. Round your answer to two decimal places.

ANSWER:

(0.82, 0.96)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/3/2019 1:55 AM 96. Some people claim there are health benefits of eating less meat. A health club committee reported the

proportion of vegetarians in their city is 0.13. Suppose this estimate was based on a random sample of 80 people. Construct a 99% confidence interval for p, the true proportion of all vegetarian eaters in this particular city. Round your answer to two decimal places.

ANSWER:

(0.03, 0.23)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/3/2019 2:04 AM 97. An airport bus driver conducted a study to see what proportion of customers use the shuttle bus to get to and

from the parking lot. The results of his study are listed below, where B = customer used the bus and W = customer walked.

Chapter 08 - Large-Sample Estimation

Construct a 95% confidence interval for p, the true proportion of all people who used the bus. Round your answer to three decimal places.

Construct a 90% confidence interval for p, the true proportion of all people who used the bus. Round your answer to two decimal places.

ANSWER:

(0.488, 0.762); (0.51, 0.74)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/3/2019 2:18 AM 98. A childcare agency wants to count the amount that families spend per child per month for childcare out of

home. A random sample of 64 families was selected. The mean and standard deviation were computed to be $675 and $80, respectively. Find a 95% confidence interval for the true average amount spent per child per month for childcare out of home. Round your answer to one decimal place.

Interpret the interval.

A social worker claims that the average amount spent per child per month out of home is $700. Based on the interval above, can this claim be rejected?

Justify your answer.

ANSWER:

(655.4, 694.6); One can estimate with 95% confidence that the true average amount spent per child per month for childcare out of home is between $655.40 and $694.60.; Yes; Since $700 is outside the limits of the 95% confidence interval, one

Chapter 08 - Large-Sample Estimation

can conclude, with 95% confidence, the claim is in error. POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/3/2019 2:28 AM 99. The manufacturer of a particular battery pack for a laptop computer claims the battery pack can function for

8 hours, on the average, before having to be recharged. A random sample of 36 such battery packs was selected and tested. The mean and standard deviation were found to be 6 hours and 1.8 hours, respectively. Find a 90% confidence interval for the true average time the battery pack can function before having to be recharged.

Based on the interval above, can the manufacturer's claim be rejected?

Explain.

ANSWER:

(5.5065, 6.4935); Yes; Since 8 is outside the limits of the 90% confidence interval, one can conclude, with 90% confidence, the claim is in error.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 100. A student government representative at a local university claims that 60% of the undergraduate students

favor a move to Division I in college football. A random sample of 250 undergraduate students was selected and 140 students indicated they favored a move to Division I. Find a 95% confidence interval for the true proportion of undergraduate students who favor the move to Division I. Round your answers to four decimal places.

Based on the interval above, can the representative's claim be rejected?

Chapter 08 - Large-Sample Estimation

Explain.

ANSWER:

(0.4985, 0.6215); No; Since 0.60 is within the limits of the 95% confidence interval, the claim cannot be rejected.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/12/2019 7:16 AM 101. A TV pollster believes that 70% of all TV households would be tuned in to Game 6 of the 1997 NBA

Championship series between the Chicago Bulls and the Utah Jazz. A random sample of 500 TV households was selected and 365 indicated they were tuned into the game. Find a 99% confidence interval for the true proportion of TV households tuned in to the game. Round your answers to four decimal places.

Based on the interval above, can the pollster's claim be rejected?

Explain.

ANSWER:

(0.6788, 0.7812); No; Since 0.70 is within the limits of the 99% confidence interval, the claim cannot be rejected.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/12/2019 7:22 AM 102. A social worker was interested in determining whether there is a significant difference in the average

monthly cost per child for childcare outside the home between state supported facilities and privately owned facilities. Two independent random samples were selected yielding the following information:

Chapter 08 - Large-Sample Estimation

Find a 90% confidence interval for the true difference in average monthly cost of the childcare.

Based on the interval above, can one conclude there is a significant difference in average cost of childcare between the state supported facilities and privately owned facilities?

Explain.

ANSWER:

(24.462, 75.538); Yes; Since 0 is not within the limits of the confidence interval, it is not likely the means are the same. Therefore one can conclude there is a difference in the average cost of childcare between the state supported facilities and privately owned facilities.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 103. A statistician knows that the population of light bulb lifetimes is normally distributed and has a standard

deviation of 30 hours. A simple random sample of 36 bulbs yields a mean lifetime of 504 hours. Construct a 99% confidence interval for the mean lifetime of all such bulbs. Round your answers to one decimal places.

Interpret the interval.

ANSWER:

(491.1, 516.9); The statistician can be 99% confident that light bulbs last between 491.1 and 516.9 hours on the average.

POINTS: QUESTION TYPE:

1 Subjective Short Answer

Chapter 08 - Large-Sample Estimation HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/12/2019 7:33 AM 104. Suppose a 95% confidence interval for the mean height of a 12-year-old male in the United States is 54 to

65 inches. In repeated sampling, 95% of the intervals constructed will contain the interval from 54 to 65 inches. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 105. Suppose a 90% confidence interval for the mean time it takes to serve a customer at a drive-in bank is 120

seconds to 220 seconds. In repeated sampling 90% of the intervals constructed using the appropriate formula will contain the actual mean time. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 106. Suppose a 90% confidence interval for the mean time it takes to serve a customer at a drive-in bank is 120

seconds to 220 seconds. At the 90% confidence level, there is not enough evidence to conclude that the mean service time is not 200 seconds. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 107. The difference between two sample means

population means a. True b. False

is an unbiased estimator of the difference between two

Chapter 08 - Large-Sample Estimation ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 108. The best estimator of the difference between two population means

sample means

is the difference between two

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 109. The standard error of the sampling distribution of

SE =

is given by the formula:

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 110. When two independent random samples of sizes

and

have been selected from populations with means

and and variances and , the standard error of the sampling distribution of the difference between the two sample means, is found by taking the square root of the sum of the two population variances; namely,

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False

Chapter 08 - Large-Sample Estimation HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 111. In estimating the difference between two population means, if a 90% confidence interval estimate includes

zero, then we can conclude that there is a 90% chance that the difference between the two population means is zero. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 112. Increasing the confidence level for a confidence interval estimate for the difference between two population

means, with all other things held constant, will result in a wider confidence interval estimate. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 113. Two samples are said to be independent if they are selected at different points in time. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 114. In constructing a 95% confidence interval estimate for the difference between the means of two normally

distributed populations, where the unknown population variances are assumed not to be equal, summary statistics computed from two independent samples are: The upper confidence limit is: a. 18.78 b. 6.78 c. 5.76

, and

Chapter 08 - Large-Sample Estimation d. 77.3 e. 89.3 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 115. When two independent random samples of sizes

and

, and variances

and

have been selected from populations with means

and

, which of the following is true?

The standard error of

is estimated as

a. The mean of b.

d. All of these. e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 116. In developing a confidence interval estimate for the difference between two population means, an increase

in the size of the samples will result in: a. a wider confidence interval b. a narrower confidence interval c. a smaller critical value z d. the same confidence interval e. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM

Chapter 08 - Large-Sample Estimation 117. When two independent random samples of sizes

and

, and variances

and

have been selected from populations with means

, which of the following is true?

a. If the sampled populations are normally distributed, then the sampling distribution of

exactly normal only when

and

are both 30 or more.

b. If the sampled populations are normally distributed, then the sampling distribution of

exactly normal regardless of the sizes of

and

c. If the sampled populations are not normally distributed, then the sampling distribution of

approximately normally distributed regardless of the sizes of

and

d. If the sampled populations are not normally distributed, then the sampling distribution of

approximately normally distributed only if e. None of these.

is 30 or more.

ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 118. If you wish to estimate the difference between two population means when the population variances are

known, the 90% confidence interval estimate can be developed using which of the following critical values of z? a. 2.33 b. 1.28 c. 1.96 d. 2.58 e. 1.645 ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 2/4/2019 9:19 AM 119. If you wish to estimate the difference between two population means when the population variances are

known, the 99% confidence interval estimate can be developed using which of the following critical values of z? a. 2.58 b. 1.645 c. 2.33 d. 1.28

Chapter 08 - Large-Sample Estimation e. 2.59 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/12/2019 7:39 AM 120. A comparison between the average jail time of bank robbers and car thieves yielded the following results

(in years):

Estimate (

), the difference in mean years of jail time.

Find the margin of error for your estimate. Round your answer to three decimal places.

ANSWER:

0.4; 0.195

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/15/2019 12:57 AM 121. A parent believes the average height for 14-year-old girls differs from that of 14-year-old boys. The

summary data are listed below where height is in feet.

Estimate the difference in the height between girls and boys using a 95% confidence interval. Round your answer to two decimal places.

Based on your interval, do you think there is a significant difference between the true mean height of 14-yearold girls and boys?

Explain.

Chapter 08 - Large-Sample Estimation ANSWER:

(0.19, 0.41); Yes; Since this interval does not contain zero, the sample data support that the heights of girls and boys differ.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/15/2019 12:58 AM 122. A dieter believes that the average number of calories in a homemade peanut butter cookie is more than in a

store-bought peanut butter cookie. The summary data are listed below.

Estimate the difference in the mean calories between the two types of cookies using a 90% confidence interval. Round your answer to two decimal places.

ANSWER:

(-0.11, 2.11)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/15/2019 12:59 AM 123. It is of interest to know if the average time it takes police to reach the scene of an accident differs from that

of an ambulance to reach the same accident. Use the summary data listed below where time is in minutes.

Estimate the difference in the times between the police and the ambulance using a 99% confidence interval. Round your answer to three decimal places.

Does it appear that the times differ?

ANSWER:

(-0.445, -0.155); Yes

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic

Chapter 08 - Large-Sample Estimation DATE CREATED: DATE MODIFIED:

2/4/2019 9:19 AM 4/15/2019 1:00 AM

124. A computer laboratory manager was in charge of purchasing new battery packs for her lab of laptop

computers. She narrowed her choices to two models that were available for her machines. Since the two models cost about the same, she was interested in determining whether there was a difference in the average time the battery packs would function before needing to be recharged. She took two independent random samples and computed the following summary information:

Find a 95% confidence interval for the difference in average functioning time before recharging in the two models. Round your answer to three decimal places.

Based on the interval above, can one conclude there is a difference in the true average functioning time before recharging between the two models of battery packs?

Explain.

ANSWER:

(-1.632, 0.632); No; Since 0 is within the limits of the confidence interval, it is possible that the means are the same. Therefore one cannot conclude there is a difference in average functioning time before recharging between the two models of battery packs.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/15/2019 1:07 AM 125. The meat department of a local supermarket packages ground beef using meat trays of two sizes: one

designed to hold approximately 1.5 pounds of meat, and one that holds approximately 3 pounds. A random sample of 36 packages in the smaller meat trays produced weight measurements with an average of 1.51 pounds and a standard deviation of 0.20 pound. (a) Construct a 99% confidence interval for the average weight of all packages sold in the small meat trays by this supermarket chain. Round your answer to four decimal places.

Chapter 08 - Large-Sample Estimation

(b) What does the phrase "99% confident" mean?

(c) Suppose that the quality control department of this supermarket chain intends that the amount of ground beef in the smaller trays should be 1.5 pound on average. Should the confidence interval in part (a) concern the quality control department?

(d) Explain.

ANSWER:

(1.4242, 1.5958); In repeated sampling, 99% of all intervals constructed in this manner will enclose mu.; No; Since the value 1.5 is contained in the interval in the previous question, it is one of several possible values for mu. The quality control department would have no reason to be concerned that the trays are being over or under-filled.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/15/2019 1:10 AM 126. An Internet server conducted a survey of 400 of its customers and found that the average amount of time

spent online was 12.5 hours per week with a standard deviation of 5.4 hours. What shape do you think the random variable x, the number of hours spent online, has?

If the distribution of the original measurements is not normal, you can still use the standard normal distribution to construct a confidence interval for , the average online time for all users of this Internet server. Why?

Construct a 95% confidence interval for the average online time for all users of the particular Internet server. Round your answer to four decimal places.

If the Internet server claimed that its users averaged 15 hours of use per week, would you agree or disagree?

Explain.

Chapter 08 - Large-Sample Estimation

ANSWER:

Skewed right; As long as the sample size n is large (in this case n = 400), the Central Limit Theorem will guarantee the approximate normality of the sampling distribution of mu, which is the basic statistic used in the large sample confidence interval.; (11.9708, 13.0292); Disagree; Since the value 15 is not contained in the confidence interval, it is not one of the likely values for mu.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/15/2019 1:12 AM 127. A study was conducted to compare the mean numbers of police emergency calls per 8-hour shift in two

districts of Los Angeles. Samples of 100 8-shifts were randomly selected from the police records for each of the two regions, and the number of emergency calls was recorded for each shift. The sample statistics are listed below:

Find a 90% confidence interval for the difference in the mean numbers of police emergency calls per shift between the two districts of the city. Round your answer to four decimal places.

Interpret the interval.

ANSWER:

(-1.0482, -0.3518); One can estimate with 90% confidence that the difference in the mean numbers of police emergency calls per shift between the two districts of Los Angeles is between -1.0482 and -0.3518. In repeated sampling, all intervals constructed in this manner will enclose

90% of the time. Hence, we are

fairly certain that this particular interval encloses

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/15/2019 1:34 AM 128. An experiment was conducted to compare two diets A and B designed for weight reduction. Two groups of

50 overweight dieters each were randomly selected. One group was placed on diet A and the other on diet B,

Chapter 08 - Large-Sample Estimation

and their weight losses were recorded over a 30-day period. The means and standard deviations of the weightloss measurements for the two groups are shown in the table.

Find a 95% confidence interval for the difference in mean weight loss for the two diets. Round your answer to four decimal places.

Interpret the interval.

ANSWER:

(7.0654, 8.7346); One can estimate with 95% confidence that the difference in the mean weight loss for the two diets is roughly between 7.07 and 8.73 pounds. In repeated sampling, all intervals constructed in this manner will enclose 95% of the time. Hence, we are fairly certain that this particular interval encloses .

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:19 AM DATE MODIFIED: 4/15/2019 1:34 AM 129. A simple extension of the estimation of a binomial proportion p is the estimation of the difference between

two binomial proportions

and

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:20 AM DATE MODIFIED: 2/4/2019 9:20 AM 130. The mean of the sampling distribution of

difference between population proportions. a. True b. False ANSWER: POINTS:

True 1

, the difference between sample proportions, is

the

Chapter 08 - Large-Sample Estimation QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:20 AM DATE MODIFIED: 2/4/2019 9:20 AM 131. Assume that two independent random samples of sizes

populations with parameters

and

and have been selected from binomial , respectively. The standard error of the sampling distribution of

the difference between sample proportions, is estimated by

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:20 AM DATE MODIFIED: 2/4/2019 9:20 AM 132. Assume that two independent random samples of sizes

and have been selected from binomial populations with parameters and , respectively. The sampling distribution of , the difference between sample proportions, can be approximated by a normal distribution provided that , and are all greater than 5. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:20 AM DATE MODIFIED: 2/4/2019 9:20 AM 133. Two independent random samples of sizes

populations with parameters and point estimation of the difference

and have been selected from binomial , respectively, and resulted in 38 and 65 success, respectively. Then, the is -27.

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:20 AM DATE MODIFIED: 2/4/2019 9:20 AM 134. Two independent random samples of sizes

and

have been selected from binomial

Chapter 08 - Large-Sample Estimation

populations with parameters and , respectively, and resulted in 38 and 65 success, respectively. Then the standard error of is estimated as .077. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:20 AM DATE MODIFIED: 2/4/2019 9:20 AM 135. If a 90% confidence interval estimate for the difference between two population proportions is to be

constructed, then the confidence coefficient would be: a. 10 b. 90 c. 05 d. 45 e. 35 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:20 AM DATE MODIFIED: 2/4/2019 9:20 AM 136. If we wish to construct a 95% confidence interval estimate for the difference between two population

proportions, then the confidence level would be: a. 1.96 b. 0.475 c. 0.95 d. 0.05 e. 2.33 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:20 AM DATE MODIFIED: 2/4/2019 9:20 AM 137. The z-value needed to construct a 97.8% confidence interval estimate for the difference between two

population proportions is: a. 2.33 b. 2.29

Chapter 08 - Large-Sample Estimation c. 2.02 d. 1.96 e. 1.65 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:20 AM DATE MODIFIED: 2/4/2019 9:20 AM 138. The z-value needed to construct a 92.5% confidence interval estimate for the difference between two

population proportions is: a. 2.58 b. 2.33 c. 1.96 d. 1.78 e. 1.33 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:20 AM DATE MODIFIED: 2/4/2019 9:20 AM 139. A stylist at The Hair Care Palace gathered data on the number of hair colorings given on Saturdays and on

weekdays. Her results are listed below. Assume the two samples were independently taken from normal populations.

Find the point estimate of p1 - p2.

Find the margin of error. Round your answer to three decimal places.

Estimate the difference in the true proportions with a 99% confidence interval. Round your answer to three decimal places.

Interpret this interval.

Chapter 08 - Large-Sample Estimation

ANSWER:

0.08; 0.158; (-0.128, 0.288); Since this interval contains zero, it is highly possible that there may be no difference in these proportions.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:20 AM DATE MODIFIED: 4/15/2019 1:37 AM 140. A manufacturing plant has two assembly lines for producing glass bottles. The plant manager was

concerned about whether the proportion of defective bottles differs between the two lines. Two independent random samples were selected and the following summary data computed:

Find a 95% confidence interval for the true difference in proportion of defective bottles produced by the two assembly lines. Round your answer to four decimal places.

Based on the interval above, can one conclude there is a difference in proportion of defective bottles produced by the two lines?

Explain.

ANSWER:

(-0.1183, 0.0583); No; Since 0 is within the limits of the confidence interval, it is possible the proportion of defective bottles produced by the two assembly lines are the same. Therefore one cannot conclude there is a difference in the proportion of defective bottles produced by the two lines.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:20 AM DATE MODIFIED: 4/15/2019 1:38 AM 141. Instead of paying to support welfare recipients, many Californians want them to find jobs; if necessary,

they want the state to create public service jobs for those who cannot find jobs in private industry. In a survey of 800 registered voters, 400 Republicans and 400 Democrats, 75% of the Republicans and 90% of the Democrats

Chapter 08 - Large-Sample Estimation

favored the creation of public service jobs. Use a large-sample estimation procedure to compare the proportions of Republicans and Democrats who favor creating public service jobs in the population of registered voters in California. The approximate 95% confidence interval is : (Round your answer to four decimal places.) Based on the interval above, is there a difference in the proportion of Republicans and Democrats who favor creating public service jobs in California?

Explain.

ANSWER:

(-0.2016, -0.0984); Yes; Since the value 0 is not in the confidence interval, it is not likely that p1 = p2. We should conclude that there is a difference in the proportion of Republicans and Democrats who favor creating public service jobs in California. It appears that the percentage of Democratic voters is higher than the Republican percentage.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:20 AM DATE MODIFIED: 4/15/2019 1:47 AM 142. In a study of the relationship between birth order and college success, an investigator found that 140 in a

sample of 200 college graduates were firstborn or only children. In a sample of 120 non-graduates of comparable age and socioeconomic background, the number of firstborn or only children was 66. Estimate the difference between the proportions of firstborn or only children in the two populations from which these samples were drawn. Use a 90% confidence interval and interpret your results. The approximate 90% confidence interval is: Round your answer to three decimal places. Based on the interval above, is there a difference between the proportions of firstborn or only children in the two populations?

Explain.

ANSWER:

(0.058, 0.242); Yes; One can estimate with 90% confidence that the difference

Chapter 08 - Large-Sample Estimation

between the proportions of firstborn or only children in the two populations from which these samples were drawn is roughly between 0.06 and 0.24. POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:20 AM DATE MODIFIED: 4/15/2019 1:48 AM 143. One-sided confidence bounds can be constructed for the population mean and population proportion p, but

not for the difference between population means, or proportions.

the difference between population

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 2/4/2019 9:21 AM 144. A 95% lower confidence bound (LCB) for the population mean can be constructed using the following

equation: LCB = a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 2/4/2019 9:21 AM 145. A 90% upper confidence bound (UCB) for the population proportion p can be constructed using the

following equation: UCB = a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False

Chapter 08 - Large-Sample Estimation HAS VARIABLES: False DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 2/4/2019 9:21 AM 146. A 95% lower confidence bound (LCB) for the difference between population proportions can be

constructed using the following equation:

LCB = a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 2/4/2019 9:21 AM 147. A 99% upper confidence bound (UCB) for the difference between population means in case of large

samples (both

and

greater than 30) can be constructed using the following equation:

UCB = a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 2/4/2019 9:21 AM 148. The sample size needed to estimate a population mean within 1.5 units with a 95% confidence when the

population standard deviation equals 10 is: a. 121 b. 13 c. 171 d. 54 e. 88 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice

Chapter 08 - Large-Sample Estimation HAS VARIABLES: False DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 2/4/2019 9:21 AM 149. If you wish to construct 80% lower confidence bound (LCB) for the population mean , then the z-value

you should use is approximately: a. .84 b. 1.28 c. 1.96 d. 2.33 e. 2.58 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 2/4/2019 9:21 AM 150. If you wish to construct 85% upper confidence bound (UCB) for the population proportion p, then the z-

value you should use is approximately: a. 2.58 b. 2.33 c. 1.96 d. 1.65 e. 1.04 ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 2/4/2019 9:21 AM 151. If you wish to construct 92% lower confidence bound (LCB) for the difference between population means

in case of large samples, then the z-value you should use is approximately: a. 2.58 b. 1.96 c. 1.65 d. 1.41 e. 1.06 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False

Chapter 08 - Large-Sample Estimation DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 2/4/2019 9:21 AM 152. If you wish to construct 98% upper confidence bound (UCB) for the difference between population

proportions, then the approximate z-value you should use is: a. 2.33 b. 2.05 c. 1.96 d. 1.65 e. 1.41 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 2/4/2019 9:21 AM 153. Suppose you wish to estimate a population proportion p based on sample of n observations. How

large should a sample be if you want your estimate to be within .03 of p with probability equal to 0.90? a. 752 b. 423 c. 1,068 d. 1.529 e. none of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 4/15/2019 2:03 AM 154. Suppose you wish to estimate a population mean based on a sample of n observations. How large should a

sample be if you want your estimate to be within 2 of with probability equal to 0.95 if you know the population standard deviation is 12? a. 239 b. 196 c. 139 d. 127 e. 98 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice

Chapter 08 - Large-Sample Estimation HAS VARIABLES: False DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 4/15/2019 2:02 AM 155. A quality control engineer wants to determine what proportion of defective parts are coming off the

assembly line. Past experiments based on large sample sizes show this proportion to be 0.19. How large a sample sould the engineer take in order to estimate this proportion with a margin of error of 0.12 with 90% confidence?

ANSWER:

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 4/15/2019 2:07 AM 156. A researcher wants to determine the proportion of elm trees in Superior, Wisconsin, dying of Dutch elm

disease. Past experiments based on large sample sizes have shown this proportion to be 0.3. How large a sample should the researcher take in order to estimate this proportion to within 0.04 with 95% confidence?

ANSWER:

505

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 4/15/2019 2:08 AM 157. A laboratory technician is interested in the proportion of 1-liter containers used in the lab that are glass.

How many containers should be sampled in order to estimate this proportion with a margin of error of less than 0.2 with 99% confidence?

ANSWER:

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 2/4/2019 9:21 AM

Chapter 08 - Large-Sample Estimation 158. A state job service employee wishes to estimate the mean number of people who register with the service

each week. How many weeks should be sampled in order to estimate the mean number of weekly registrants? The employee would like the margin of error to be less than 0.5 with probability of 0.95. Past records show the weekly standard deviation to be 2.5.

weeks ANSWER:

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 2/4/2019 9:21 AM 159. In a study of radio listening habits, a station owner would like to estimate the average number of hours that

teenagers spend listening each day. If it is reasonable to assume that = 1.3 hours, how large a sample size is needed to be 90% confident that the sample mean is off by at most 30 minutes?

ANSWER:

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 2/4/2019 9:21 AM 160. Trish attends an aerobics class four times each week. She would like to estimate the mean number of

minutes of continuous exercise until her heart reaches 90 beats per minute. If it can be assumed that = 1.7 minutes, how large a sample is needed so that it will be possible to assert with 99% confidence that the sample mean has a margin of error of at most 0.62 minutes?

ANSWER:

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 4/15/2019 2:08 AM 161. The Postmaster at the Harrington Post Office would like to compare the delivery times to two different

locations which are the same number of miles from Harrington. A random sample of letters are to be divided into two equal groups, the first delivered to Location A and the second delivered to Location B. Each letter will

Chapter 08 - Large-Sample Estimation

be delivered on a randomly selected day and the number of days for each letter to arrive at its destination is recorded. The measurements for both groups are expected to have a range (variability) of approximately 4 days. If the estimate of the difference in mean delivery times is desired to be correct to within 1 day with probability equal to 0.99, how many letters must be included in each group? Assume n1 = n2 = n.

ANSWER:

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 2/4/2019 9:21 AM 162. It is desired to compare the average ages at which men and women get their first license to drive. A random

sample of 75 men yielded a mean and standard deviation of 17.3 and 4.7 years, respectively. A random sample of 96 women yielded a mean and standard deviation of 19.6 and 5.1 years, respectively. If it is desired to estimate the mean difference to within 1.5 years with 95% confidence, how large a sample should be taken from each population? Assume n1 = n2 = n.

ANSWER:

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 2/4/2019 9:21 AM 163. A childcare agency was interested in examining the amount that families pay per child per month for

childcare outside the home. A random sample of 64 families was selected and the mean and standard deviation were computed to be $675 and $80, respectively. Find a 95% upper confidence bound for the true average amount spent per child per month on childcare outside the home. Round your answer to two dacimal places.

ANSWER:

691.45

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:21 AM

Chapter 08 - Large-Sample Estimation DATE MODIFIED:

4/15/2019 2:11 AM

164. The manufacturer of a particular battery pack for a laptop computer claims the battery pack can function

for 8 hours, on the average, before having to be recharged. A random sample of 36 such battery packs was selected and tested. The mean and standard deviation were found to be 6 hours and 1.8 hours, respectively. Find a 95% lower confidence bound for the true average time the battery pack can function before having to be recharged. Round your answer to four decimal places.

ANSWER:

5.5065

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 4/15/2019 2:13 AM 165. A machine produces aluminum tins used in packaging cheese. A random sample of 1000 tins was selected

and 43 were found to be defective. Find a 95% upper confidence bound for the true proportion of defective tins produced by the machine. Round your answer to four decimal places.

ANSWER:

0.0536

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 4/15/2019 2:13 AM 166. A manufacturer wishes to estimate the mean time a battery pack will function before needing to be

recharged with a margin of error of no more than 0.5 hours and with probability 0.95. If the standard deviation is known to be 1.5 hours, how many observations should be included in the sample?

ANSWER:

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 2/4/2019 9:21 AM

Chapter 08 - Large-Sample Estimation 167. A process control engineer wishes to estimate the true proportion of defective computer chips with a

margin of error of no more than 0.09 and with probability 0.90. How many observations does the engineer need to include in the sample to achieve his goal?

ANSWER:

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 2/4/2019 9:21 AM 168. Suppose you wish to estimate a population mean based on a random sample of n observations, and prior

experience suggests that . If you wish to estimate correct to within 1.8, with probability equal to 0.95, how many observations should be included in your sample?

ANSWER:

207

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 4/15/2019 2:15 AM 169. A questionnaire is designed to investigate attitudes about political corruption in government. The

experimenter would like to survey two different groups--Republicans and Democrats--and compare the responses to various "yes-no" questions for the two groups. The experimenter requires that the sampling error for the difference in the proportion of yes responses for the two groups is no more than 4 percentage points with probability equal to 0.95. If the two samples are both the same size, how large should the samples be?

ANSWER:

1201

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 2/4/2019 9:21 AM 170. You want to estimate the difference in grade point averages between two groups of college students

accurate to within 0.20 grade point, with probability equal to 0.95. If the standard deviation of the grade point measurements is approximately equal to 0.5, how many students must be included in each group? (Assume that

Chapter 08 - Large-Sample Estimation

the groups will be of equal size.)

ANSWER:

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 2/4/2019 9:21 AM 171. Assume that the population standard deviation of annual incomes of all Michigan residents is $2,500. How

many individuals must we include in a simple random sample if we want to be 95% confident that the population mean incomes lies within $150 of our sample mean income?

ANSWER:

1068

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 2/4/2019 9:21 AM 172. An airline executive estimates that 25% of all flights arrive late. How many flights must we include in a

simple random sample if we want to be 90% confident that the true population proportion of flights that arrive late lies within 0.01 of our sample proportion?

ANSWER:

5074

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:21 AM DATE MODIFIED: 2/4/2019 9:21 AM

Chapter 09 - Large-Sample Tests of Hypotheses 1. A Type I error for a statistical test is committed if we reject the null hypothesis when it is true. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 2. The p-value is usually 0.025. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 3. A Type II error for a statistical test is committed if we do not reject the null hypothesis when it is false. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 4. The p-value of a statistical test is the largest value of the significance level

for which the null hypothesis can

be rejected. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 5. The power of a statistical test, denoted by 1 a. True b. False

, is the probability of rejecting a false null hypothesis.

Chapter 09 - Large-Sample Tests of Hypotheses ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 6. For a fixed sample size n, as the probability of a Type II error decreases, the probability of a Type I error

increases. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 7. A two-tailed test is a test in which a null hypothesis can be rejected by an extreme result occurring in only

one direction. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 4/2/2019 3:48 AM 8. A Type I error is represented by , and is the probability of not rejecting a false null hypothesis. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 9. As the significance level

region increases. a. True b. False ANSWER:

True

increases, the probability of a Type I error increases and the size of the rejection

Chapter 09 - Large-Sample Tests of Hypotheses POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 10. Reducing the probability of a Type I error also reduces the probability of a Type II error. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 11. In a one-tailed test, the p-value is found to be equal to 0.036. If the test had been two-tailed, the p-value

would have been 0.072. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 12. In order to calculate the p-value associated with a test, it is necessary to know the level of significance a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM

13. A professor of mathematics refutes the claim that the average student spends 4.5 hours studying for the final

comprehensive exam. To test the claim, the hypothesis: H0: μ = 4.5, H1: μ ≠ 4.5, should be used. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False

Chapter 09 - Large-Sample Tests of Hypotheses HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 4/2/2019 3:54 AM 14. When the necessary conditions are met, a two-tailed test is being conducted to test the difference between

two population means, but your statistical software provides only a one-tailed area of 0.156 as part of its output. The p-value for this test will be 0.078. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 4/2/2019 3:57 AM 15. Hypothesis testing is a systematic approach to assessing tentative beliefs about reality, which involves

confronting those beliefs with evidence and deciding, in light of this evidence, whether the beliefs can be maintained as reasonable or must be discarded as untenable. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 16. The null hypothesis is a vehicle for making startling new claims that contradict the conventional wisdom,

that assert "guilt without a reasonable doubt." a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 17. If the null hypothesis, H0, cannot be corroborated in a hypothesis test,

calls for action; thus, one can think of a. True b. False ANSWER:

True

as the action hypothesis.

is tentatively embraced, which

Chapter 09 - Large-Sample Tests of Hypotheses POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 18. The alternative hypothesis is a description of the status quo, of conventional wisdom, of a "state of innocence," of what people have long believed to be true. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 19. If H0 is corroborated in a hypothesis test, no action need be taken by anyone. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 20. A hypothesis that specifies a single value for the unknown parameter is called a point estimate. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 21. A hypothesis that specifies a range of values for the unknown parameter is called an interval estimate. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False

Chapter 09 - Large-Sample Tests of Hypotheses DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 22. An alternative hypothesis that holds for deviations from the null hypothesis in either direction is a two-tailed

hypothesis. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 4/2/2019 4:44 AM 23. An alternative hypothesis that holds for deviations from the null hypothesis in one direction only is a one-

tailed hypothesis. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 4/2/2019 4:45 AM 24. A p-value is a statistic computed from a simple random sample taken from the population of interest in a

hypothesis test and then used for establishing the probable truth or falsity of the null hypothesis. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 25. The p-value in hypothesis testing equals the probability, 1 -

rejecting a null hypothesis that is in fact true. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM

, of avoiding the Type I error of erroneously

Chapter 09 - Large-Sample Tests of Hypotheses DATE MODIFIED: 2/4/2019 9:23 AM 26. A set consisting of values that support the alternative hypothesis and lead to rejecting the null hypothesis is

called the rejection region. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 27. In hypothesis testing, the statement of the null hypothesis always contains the equality sign. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 4/2/2019 4:11 AM 28. In hypothesis testing, the decision to "accept" the null hypothesis is the same as the decision to "fail to

reject" the null hypothesis. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 29. A two-tailed test of hypothesis for a population mean with a significance level

critical value z equal to .475. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM

equal to .05 will have a

Chapter 09 - Large-Sample Tests of Hypotheses 30. In a hypothesis test, if the null hypothesis has been rejected, then it is impossible that a Type II error has

been committed. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 31. In a one-tailed test, the larger the significance level a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM

, the larger the critical value will be.

32. If you wish to conduct a hypothesis test using a small significance level

, you should decrease β to avoid

committing a Type II error. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 4/2/2019 5:15 AM 33. Decision makers have most control over Type I error than Type II error. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 34. If the null hypothesis is actually false, then a hypothesis test may result in a Type II error. a. True

Chapter 09 - Large-Sample Tests of Hypotheses b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 35. If a hypothesis test leads to incorrectly rejecting the null hypothesis, a Type II error has been committed. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 36. If a hypothesis test leads to incorrectly accepting the null hypothesis, a Type I error has been committed. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 37. A statistics professor has claimed that her top student will average more than 98 points in the final exam. If

you wish to test this claim, you would formulate the following null and alternative hypotheses: H0: μ = 98 vs. Ha: μ > 98. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 4/2/2019 4:58 AM 38. If the probability of committing a Type I error is set at 0.10, then the probability of committing a Type II

error will be 0.90, since the sum of probabilities must be 1.0. a. True b. False

Chapter 09 - Large-Sample Tests of Hypotheses ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 4/2/2019 4:59 AM 39. A two-tailed hypothesis test of the population mean is used when the alternative hypothesis takes the form

Ha: μ ≠ μ0. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 4/2/2019 5:01 AM 40. With all other factors held constant, the chance of committing a Type II error increases if the true population

mean is closer to the hypothesized value

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 41. If a decision maker is concerned that the chance of committing a Type II error is large, one way that will

help reduce the risk is to increase the significance level. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 42. The p-value or observed significance level measures the strength of the evidence against the alternative

hypothesis. a. True b. False

Chapter 09 - Large-Sample Tests of Hypotheses ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 43. If the p-value for a hypothesis test is less than a preassigned significance level

, then the null hypothesis can be rejected, and you can report that the results are statistically significant at level . a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 44. Type II error is typically greater for two-tailed hypothesis tests than for one-tailed tests. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 45. The p-value for a hypothesis test is set up by the decision maker to minimize the probability of committing a

Type I error. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 46. A quality control officer tests bottles of shampoo to see if the filling machines are putting the proper amount

in each bottle. They do not want to shut down production unless there is strong evidence indicating that the machines are not functioning properly. After testing a sample of bottles, the quality control officer decides to leave the filling machines operating. Actually, however, the filling machines are not operating properly. Which type of error, if any, did the quality control officer commit? a. This is a Type I error.

Chapter 09 - Large-Sample Tests of Hypotheses b. This is a Type II error. c. This is a Type O error. d. This is a correct decision. e. Need more information to answer this question. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 47. A Type I error is committed when we: a. reject a true null hypothesis b. reject a false null hypothesis c. don't reject a false null hypothesis d. don't reject a true null hypothesis e. do none of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 48. A government testing agency studies aspirin capsules to see if customers are getting cheated with capsules

that contain lesser amounts of medication than advertised. Suppose the testing agent concludes the capsules contain a mean amount below the advertised level when in fact the advertised level is the true mean. Which type of error, if any, did the testing agency commit? a. This is a Type I error. b. This is a Type II error. c. This is a Type O error. d. This is a correct decision. e. Need more information to answer this question. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 49. If we reject the null hypothesis, we conclude that: a. there is not enough statistical evidence to infer that the alternative hypothesis is true b. there is enough statistical evidence to infer that the alternative hypothesis is true

Chapter 09 - Large-Sample Tests of Hypotheses c. there is not enough statistical evidence to infer that the null hypothesis is true d. there is enough statistical evidence to infer that the null hypothesis is true e. the test is statistically insignificant at whatever level of significance the test was conducted at ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 50. In a criminal trial, a Type I error is committed when: a. a guilty defendant is acquitted b. an innocent person is convicted c. a guilty defendant is convicted d. an innocent person is acquitted e. a guilty defendant is convicted and an innocent person is acquitted ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 51. A Type II error is committed when we: a. reject a true null hypothesis b. reject a false null hypothesis c. don't reject a true null hypothesis d. don't reject a false null hypothesis e. do none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 52. The power of a test is denoted by: a. b. c. d. e. ANSWER: d

Chapter 09 - Large-Sample Tests of Hypotheses POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 53. The p-value of a test is the: a. smallest at which the null hypothesis can be rejected b. largest at which the null hypothesis can be rejected c. largest at which the null hypothesis cannot be rejected d. smallest at which the null hypothesis cannot be rejected e. largest at which the null hypothesis cannot be rejected ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 54. If we do not reject the null hypothesis, we conclude that: a. there is not enough statistical evidence to infer that the alternative hypothesis is true b. there is enough statistical evidence to infer that the alternative hypothesis is true c. there is enough statistical evidence to infer that the null hypothesis is true d. there is not enough statistical evidence to infer that the null hypothesis is true e. the test is statistically insignificant at whatever level of significance the test was conducted at ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 55. Which of the following statements is (are) not true? a. The probability of committing a Type I error increases as the probability of committing a Type II

error decreases. b. The probability of committing a Type II error and the level of significance are the same. c. The power of the test decreases as the level of significance decreases. d. The probability of committing a Type I error and the level of significance are the same and the power of the test decreases as the level of significance decreases. e. All of these. ANSWER:

POINTS:

Chapter 09 - Large-Sample Tests of Hypotheses QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 4/2/2019 5:10 AM 56. In a two-tailed test for the population mean, the null hypothesis will be rejected at

level of significance if

the value of the test statistic z is such that: a. | z | > b. | z | < – c. z > – d. | z | > e. | z | < ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 4/4/2019 5:25 AM 57. Consider testing the hypothesis:

. If the value of the test statistic is equal to 1.36,

then the p-value is: a. 0.4131 b. 0.1738 c. 0.2066 d. 0.9131 e. 0.8325 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 58. If a hypothesis is rejected at the 0.05 level of significance, it: a. must be rejected at any level b. must not be rejected at any level c. must be rejected at the 0.02 level d. must not be rejected at the 0.02 level e. may be rejected or not rejected at the 0.02 level ANSWER: e POINTS:

Chapter 09 - Large-Sample Tests of Hypotheses QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 59. In testing the hypothesis

, the following information is known: n = 64, = 78, and

10. The test statistic is equal to: a. +1.96 b. +2.4 c. -2.4 d. -1.96 e. +2.58 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 60. Which of the following p-values will lead us to reject the null hypothesis if the level of significance

0.05? a. 0.025 b. 0.06 c. 0.10 d. 0.20 e. 0.25 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 4/4/2019 5:32 AM 61. A proposition tentatively advanced as possibly true is called: a. an acceptance region b. a confidence level c. a hypothesis d. a p-value e. a z-value ANSWER: c 1 POINTS: QUESTION TYPE: Multiple Choice

Chapter 09 - Large-Sample Tests of Hypotheses HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 62. Which of the following correctly describes hypothesis testing? a. It is a systematic approach to assessing tentative beliefs about reality. b. It involves confronting beliefs with evidence and deciding, in light of this evidence, whether the

beliefs can be maintained as reasonable or must be discarded as untenable. c. It only involves statements about population parameters. d. It is a systematic approach to assessing tentative beliefs about reality and it involves confronting beliefs with evidence and deciding, in light of this evidence, whether the beliefs can be maintained as reasonable or must be discarded as untenable. e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 63. The first step in hypothesis testing is always: a. formulating two opposing hypotheses, called the null and alternative hypotheses b. selecting a test statistic c. calculating the p-value d. determining the rejection region e. determining the critical value ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 64. Which of the following statements about the null hypothesis is false? a. It is the first of two opposing hypotheses in any hypothesis test. b. It is a description of the status quo. c. It is a vehicle for making startling new claims that contradict the conventional wisdom. d. If

is corroborated in a hypothesis test, no action need be taken by anyone. e. It is the first of two opposing hypotheses in any hypothesis test and it is a description of the status quo. ANSWER: c 1 POINTS: QUESTION TYPE: Multiple Choice

Chapter 09 - Large-Sample Tests of Hypotheses HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 65. Which of the following does not correctly describe an alternative hypothesis? a. Ha: μ = μ0 b. Ha: μ > μ0 c. Ha: μ < μ0 d. Ha: μ ≠ μ0 e. H0: μ = μ0 and Ha: μ ≠ μ0 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 4/4/2019 5:41 AM 66. Which of the following is an example of a null hypothesis? a. This industrial process makes windshields with an average length of 33 inches. b. The average quantity of detergent put into a box by this filling machine is not 1 pound. c. This shipping company's average delivery time is different from 3 days. d. The thickness of aluminum sheets averages is not .03 inches, as required. e. The average quantity of detergent put into a box by this filling machine is not 1 pound and this

shipping company's average delivery time is different from 3 days. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 67. In large-sample statistical tests about the population mean , instead of using directly as the test statistic, it

is common practice to use: a.

, if is known b.

, if s is known c.

, if is known

Chapter 09 - Large-Sample Tests of Hypotheses d.

both

, if is known and

, if s is known

neither

, if is known nor

, if s is known

ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 68. Numerical values of a test statistic for which a. are said to lie in the acceptance region

is not rejected:

b. are each viewed as a not statistically significant result c. are more than the critical value d. are correctly described by “are said to lie in the acceptance region” and “are each viewed as a not

statistically significant result” e. are correctly described by neither “are said to lie in the acceptance region” nor “are each viewed as a not statistically significant result” ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 69. Which of the following statements is false? a. When the alternative hypothesis is two-tailed, any hypothesis test is said to be a two-tailed test. b. When the alternative hypothesis is two-tailed, the null hypothesis is rejected for values of the test

statistic located in either tail of that statistic's sampling distribution. c. When the alternative hypothesis is two-tailed, the rejection region is split between the two tails of the test statistic's sampling distribution. d. When the alternative hypothesis is two-tailed, the null hypothesis is rejected for values of the test statistic located in either tail of that statistic's sampling distribution and when the alternative hypothesis is two-tailed, the rejection region is split between the two tails of the test statistic's sampling distribution. e. None of these. ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM

Chapter 09 - Large-Sample Tests of Hypotheses DATE MODIFIED: 4/4/2019 5:43 AM 70. In hypothesis testing, the term critical value refers to: a. the probability, 1 - , of avoiding the Type I error of erroneously rejecting a null hypothesis that is in

fact true b. the value of a test statistic that divides all possible values into an acceptance region and a rejection region c. the probability, 1 - , of avoiding the Type O error of erroneously rejecting a null hypothesis that is in fact true d. any sample result that leads to the continued acceptance of the null hypothesis because it has a high probability of occurring when the null hypothesis is true e. the probability, 1 - , of avoiding the Type II error of erroneously accepting a null hypothesis that is in fact false ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 71. Which of the following statements about possible errors in hypothesis tests is correct? a. The probability of correctly accepting a true null hypothesis equals 1 - and is called the confidence

level of the hypothesis test b. The probability of making the Type II error of incorrectly rejecting a true null hypothesis equals and is called test's significance level or a risk c. The probability of making the Type I error of incorrectly accepting a false null hypothesis equals and is called the risk d. The probability of correctly rejecting a false null hypothesis equals and is called the power of the hypothesis test e. The probability of correctly accepting a true null hypothesis equals 1 - and is called the confidence level of the hypothesis test ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 72. Which of the following exemplifies a Type I error of incorrectly rejecting a true null hypothesis? a. Interrupting the production process in order to adjust machinery that needs no adjusting. b. Switching to a new supplier of raw materials although the performance of the old one was

satisfactory. c. Condemning a firm for ignoring pollution standards even though it has done no such thing. d. All of these.

Chapter 09 - Large-Sample Tests of Hypotheses e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 73. The erroneous acceptance of a null hypothesis that is in fact false can have consequences such as: a. interrupting the production process in order to adjust machinery that needs no adjusting b. acquitting a guilty defendant in a criminal trial c. switching to a new supplier of raw material although the performance of the old one was satisfactory d. convicting a guilty defendant in a criminal trial e. condemning a firm for ignoring pollution standards even though it has done no such thing ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 74. When formulating a hypothesis test, which of the following statements is true? a. The null hypothesis should be written in a way to minimize the probability of committing a Type I

error. b. The null hypothesis should be stated in terms of the population parameter. c. The alternative hypothesis should be stated in terms of the population parameters. d. The null hypothesis should never contain the equality. e. The null hypothesis should always contain the equality. ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 4/4/2019 5:54 AM 75. Which of the following statements is true? a. The probabilities of committing Type I and Type II errors are related such that when one is increased,

the other will increase also. b. The decision maker controls the probability of committing a Type I error. c. The probability of committing a Type I error is the represented by the Greek letter . d. The probability of committing a Type II error is the represented by the Greek letter . e. The probability of committing a Type II error is the same as the level of significance.

formulation? a. b. c. d. e. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 77. If you wish to determine there is evidence that the average starting salary for finance graduates exceeds

$42,000, then you should formulate the null and alternative hypotheses such that: a. either a two-tailed or one-tailed test could be used b. a two-tailed test should be used c. a one-tailed test should be used d. the probability of committing a Type II error is equal to 0.42 e. a two-tailed test should be used and the probability of committing a Type II error is equal to 0.42 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 4/4/2019 5:55 AM 78. In a two-tailed test, if the p-value is less than the probability of committing a Type I error, then: a. a one-tailed test should be used b. the null hypothesis should be rejected c. the null hypothesis should not be rejected d. another sample should be selected at random from the population e. the probability of a Type II error must be calculated

Chapter 09 - Large-Sample Tests of Hypotheses ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 79. If the hypothesis test is conducted using = .025, this means that: a. there is a 2.5% chance that the null hypothesis is true b. there is a maximum 2.5% chance that a false null hypothesis will be rejected c. there is a maximum 2.5% chance that a true null hypothesis will be rejected d. there is 2.5% chance of committing a Type I error and 97.5% chance of committing a Type II error e. there is a 0.25% chance that the null hypothesis is true ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 80. In testing H0: μ = 5 vs Ha: μ ≠ 5, which of the following statements is true as a result of increasing the

sample size? a. The sampling distribution of the sample mean has less variability. b. There is no effect on the level of significance for the test. c. There is no effect on whether the null hypothesis is true or false. d. All of these. e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 4/4/2019 5:57 AM 81. In formulating the null and alternative hypothesis, which of the following would be an acceptable null

hypothesis? a. The population mean is greater than 20. b. The population mean is smaller than 20. c. The population mean is equal to 20. d. The population mean is not equal to 20. e. None of these. ANSWER:

Chapter 09 - Large-Sample Tests of Hypotheses POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 82. If the probability of committing a Type I error for a given test is to be decreased, then for a fixed sample size

n, which of the following statements is true? a. The power of the test will increase. b. The probability of committing a Type II error will increase. c. The probability of committing a Type II error will decrease. d. A two-tailed test must be used. e. The probability of committing a Type II error will decrease and a two-tailed test must be used. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 83. A mail-order catalog claims that customers will receive their product within 4 days of ordering. A

competitor believes that this claim is an underestimate. State the appropriate null and alternative hypotheses to be tested by the competitor.

H0:

H1: Describe the Type I error for this problem.

Describe the Type II error for this problem.

ANSWER:

µ = 4; µ > 4; A Type I error would occur if the competitor would reject the null hypothesis when, in fact, it is true, i.e., if the competitor would conclude the mean time until the product is received is more than 4 days when, in fact, it is not.; A Type II error would occur if the competitor would not reject the null hypothesis when, in fact, it is false, i.e., if the competitor would not conclude the mean time until the product is received is more than 4 days when, in fact, it is.

Chapter 09 - Large-Sample Tests of Hypotheses POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 84. John Kerry believes that 54% of the voters are supporting him. His opponent, George W. Bush, believes this

estimate is too high. State the appropriate null and alternative hypotheses to be tested by George W. Bush.

H0:

H1: Describe the Type I error for this problem.

Describe the Type II error for this problem.

Describe the practical consequences for George W. Bush if he makes a Type I error.

Describe the practical consequences for the George W. Bush if he makes a Type II error.

ANSWER:

p = 0.54; p < 0.54; A Type I error would occur if George W. Bush would reject the null hypothesis when, in fact, it is true, i.e., if Bush would conclude the proportion of voters supporting the candidate is less than 0.54 when, in fact, it is not.; A Type II error would occur if George W. Bush would not reject the null hypothesis when, in fact, it is false, i.e., if Bush would not conclude the proportion of voters supporting the candidate is less than 0.54 when, in fact, it is.; George W. Bush may think he is doing better in the campaign than he actually is.; George W. Bush may think he is doing worse in the campaign than he actually is.

POINTS: QUESTION TYPE:

1 Subjective Short Answer

Chapter 09 - Large-Sample Tests of Hypotheses HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 85. A toaster manufacturer receives large shipments of thermal switches from a supplier. A sample from each

shipment is selected and tested. The manufacturer is willing to send the shipment back if the proportion of defective switches is more than 5%. Otherwise, the shipment will be kept. State the appropriate null and alternative hypotheses to be tested by the manufacturer.

H0:

H1: Describe the Type I error.

Describe the Type II error for this problem.

From the manufacturer's point of view, which error would be the more serious?

Justify your answer.

From the supplier's point of view, which error would be the more serious?

Justify your answer.

ANSWER:

p = 0.05; p > 0.05; A Type I error would occur if the manufacturer would reject the null hypothesis when, in fact, it is true, i.e., if the manufacturer would conclude the

Chapter 09 - Large-Sample Tests of Hypotheses

proportion of defective switches is more than 0.05 when, in fact, it is not.; A Type II error would occur if the manufacturer would not reject the null hypothesis when, in fact, it is false, i.e., if the manufacturer would not conclude the proportion defective switches is more than 0.05 when, in fact, it is.; Type II; The Type II error would be the more serious one, since the manufacturer would be keeping a shipment that actually had more than 5% defective switches.; Type I; The Type I error since the supplier would have to take back a shipment even though it does not have more than 5% defective switches. POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 86. Develop the null and appropriate hypotheses that are most appropriate for each of the following situations:

A meteorologist claims that the average high temperature for the month of August in Chicago, Illinois is 83°F. If the residents of Chicago do not believe this to be true, what hypotheses should they test? H0: H1: A car manufacturing plant is acting in accordance with the public's interest in making cars that have gas mileage of at least 28 miles per gallon. The supervisor will only let the cars off the manufacturing floor if the gas mileage is more than 28 miles per gallon. What hypotheses should the plant test? H0: H1: A spokesperson for the Health Department reports that a fish is unsafe for human consumption if the polychlorinated biphenyl (PCB) concentration exceeds 5 ppb. The Carlson family is interested in the mean PCB concentration in a fish from the lake on which they live. What hypotheses should they test? H0: H1: An Internet survey revealed that 50% of Internet users received more than 10 e-mail messages per day. A similar study on the use of e-mail was repeated. The purpose of the study was to see whether use of e-mail has increased. H0:

Chapter 09 - Large-Sample Tests of Hypotheses

H1: ANSWER:

µ = 83; µ ≠ 83; µ = 28; µ > 28; µ = 5; µ > 5; p = 0.05; p > 0.05

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 4/4/2019 6:09 AM 87. A sample of size 150 is to be used to test the hypotheses H0: = 8.3 versus H1:

8.3 where is the true average weight of a newborn American baby. Give the appropriate rejection region associated with each of the following significance levels. = 0.01 Critical Value(s) = = 0.05 Critical Value(s) = = 0.1 Critical Value(s) = ANSWER:

2.58, -2.58; 1.96, -1.96; 1.645, -1.645

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 4/4/2019 6:21 AM 88. A sample of size 80 is to be used to test the hypotheses H0: = 29 versus Ha:

29 where, is the true average age of a man when he gets married. What is the appropriate rejection region associated with each of the following significance levels. = 0.01

Critical Value(s) = = 0.005

Critical Value(s) =

Chapter 09 - Large-Sample Tests of Hypotheses

= 0.05

Critical Value(s) = = 0.1

Critical Value(s) = ANSWER:

2.575, -2.575; 2.81, -2.81; 1.96, -1.96; 1.645, -1.645

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 89. The Iowa Department of Transportation repaired hundreds of bridges in 1993. To check the average cost to

repair a bridge, a random sample of n = 55 bridges was chosen. The mean and standard deviation for the sample are $25,788 and $1,540, respectively. Records from previous years indicate an average bridge repair cost was $25,003. Use the sample data to test that the 1993 mean is greater than $25,003. Use = 0.05.

Test statistic =

Critical Value(s) =

Conclusion:

Interpretation: ANSWER:

3.78; 1.645; Reject H0; The average bridge repair cost in 1993 is greater than $25,003

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 90. A new light bulb is being considered for use in an office with computers. It is decided that the new bulb will

only be used if it has a mean lifetime of more than 500 hours. A random sample of 40 bulbs is selected and placed on life test. The mean and standard deviation are found to be 505 hours and 18 hours, respectively.

Chapter 09 - Large-Sample Tests of Hypotheses

Perform the appropriate test of hypothesis to determine whether the new bulb should be used. Use a 0.01 level of significance. Test statistic = Critical Value(s) = Conclusion: Interpretation: ANSWER:

1.76; 2.33; Do not reject H0; The new bulb should NOT be used

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 4/4/2019 6:22 AM 91. Historically, the average time it takes Jessica to swim the 200 meter butterfly is 148.4 seconds. Jessica

would like to know if her average time has changed. She records her time on 50 randomly selected occasions and computes the mean to be 147.8 seconds with a standard deviation of 2.3 seconds. Perform the appropriate test of hypothesis to determine whether Jessica's average time has changed. Use = 0.01. Test statistic = Critical Value(s) = Conclusion: Interpretation: Compute the power of the test if Jessica's actual mean swimming time is 147.3 seconds.

Interpret the results.

ANSWER:

-1.845; -2.58, 2.58; Do not reject H0; Jessica's average time has NOT changed; 0.7881; Thus the probability of correctly rejecting the null hypothesis, given that m = 147.3, is 0.7881.

POINTS:

Chapter 09 - Large-Sample Tests of Hypotheses QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 4/5/2019 3:02 AM 92. Let denote the true average delivery time of a letter from a specific carrier. For a large-sample z test of H0:

= 3 versus Ha: 3, find the p-value associated with each of the given values of the test statistic, and state whether each p-value will lead to a rejection of the null hypothesis when performing a level 0.05 test. z = 2.16 p= Conclusion: z = 0.38 p= Conclusion: z = -2.81 p= Conclusion: z = 1.07 p= Conclusion: z = -0.68 p= Conclusion: ANSWER:

0.0308; Reject H0; 0.704; Do not reject H0; 0.005; Reject H0; 0.2846; Do not reject H0; 0.4966; Do not reject H0

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic

Chapter 09 - Large-Sample Tests of Hypotheses DATE CREATED: DATE MODIFIED:

2/4/2019 9:23 AM 4/5/2019 3:45 AM

93. The manufacturer of a particular battery pack for laptop computers claims its battery pack can function for 8

hours, on the average, before having to be recharged. A random sample of 36 battery packs was selected and tested. The mean functioning time before having to be recharged was 7.2 hours with a standard deviation of 1.9 hours. A competitor claims that the manufacturer's claim is too high. Perform the appropriate test of hypothesis to determine whether the competitor is correct. Test using = 0.05.

Test statistic =

Critical Value(s) =

Conclusion:

Interpretation: Find the p-value for this test.

p-value = ANSWER:

-2.53; -1.645; Reject H0; We can reject the manufacturer's claim; 0.0057

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 94. A large university claims that the average cost of housing within three miles of the campus is $6900 per

school year. A high school student is preparing her budget for her freshman year at the university. She is concerned that the university's estimate is too low. Having taken AP Statistics, she decides to perform the following test of hypothesis: H0: = 6900 versus Ha: > 6900, where represents the average cost of housing per year within three miles of the university. Describe the Type I error for this problem.

Describe the Type II error for this problem.

Chapter 09 - Large-Sample Tests of Hypotheses

Which error has more serious consequences for the student?

ANSWER:

A Type I error would occur if the student would reject the null hypothesis when, in fact, it is true, i.e., if the student would conclude the average cost of housing is more than $6900 when, in fact, it is not.; A Type II error would occur if the student would not reject the null hypothesis when, in fact, it is false, i.e., if the student would not conclude the average cost of housing is more than $6900 when, in fact, it is.; Type II

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 95. The public relations officer for a particular city claims the average monthly cost for childcare outside the

home for a single child is $700. A potential resident is interested in whether the claim is correct. She obtains a random sample of 64 records and computes the average monthly cost of this type of childcare to be $689 with a standard deviation of $40. Perform the appropriate test of hypothesis for the potential resident using = 0.01.

Test statistic =

Critical Value(s) =

Conclusion:

Interpretation: Find the p-value for the test above.

p-value = What effect, if any, would there be on the conclusion in part (a) if you changed to 0.05?

The conclusion would

Chapter 09 - Large-Sample Tests of Hypotheses

Find the power of the test when is actually $685 and = 0.05.

ANSWER:

-2.20; -2.575, 2.575; Do not reject H0; The claim is correct; 0.0278; change; 0.8508

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 96. A random sample of n = 36 observations from a quantitative population produced a mean = 2.5 and a

standard deviation s = 0.30. Suppose your research objective is to show that the population mean exceeds 2.4. Find the standard error of the mean.

Do the data provide sufficient evidence to indicate that > 2.4. Test at = 0.05. Test statistic = Critical Value(s) = Conclusion: Interpretation: Calculate the p-value for the test statistic above. p-value = Use the p-value to draw a conclusion at the 5% significance level. Conclusion: Compare the two conclusions. Are they the same?

Find the critical value of used for rejecting H0.

Calculate = P(accept H0 when = 2.5).

Chapter 09 - Large-Sample Tests of Hypotheses

ANSWER:

0.05; 2.0; 1.645; Reject H0; The population mean exceeds 2.4; 0.0228; Reject H0; Yes; 2.48; 0.3446

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 4/5/2019 4:04 AM 97. An Internet server claimed that its users spent online averaged 15 hours per week. To determine whether this

was an overstatement, a competitor conducted a survey of 150 customers and found that the average time spent online was 13 hours per week with a standard deviation of 6.5 hours. Do the data provide sufficient evidence to indicate that the average hours of use are less than that claimed by the first Internet server? Test at the 1% level of significance. Test statistic = Critical value(s) = Conclusion: Interpretation: ANSWER:

-3.768; -2.33; Reject H0; The average time is less than claimed by the Internet server

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 4/8/2019 11:55 PM 98. The daily wages in a particular industry are normally distributed with a mean of $60 and a standard

deviation of $13. Suppose a company in this industry employs 50 workers and pays them $57.50 on the average. Based on this sample mean, can these workers be viewed as a random sample from among all workers in the industry? Find the p-value for the test.

Test statistic =

p-value =

Chapter 09 - Large-Sample Tests of Hypotheses

If you planned to conduct your test using

, what would be your test conclusions?

Conclusion:

Interpretation: ANSWER:

-1.36; 0.1738; Do not reject H0; The company is NOT paying wages different from the industry average

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 99. A manufacturer of copper pipes must produce pipes with a diameter of precisely 5 inches. The firm's quality

inspector wants to test the hypothesis that pipes of the proper size are being produced. Accordingly, a simple random sample of 100 pipes is taken from the production process. The sample mean diameter turns out to be 4.98 inches and the sample standard deviation 0.2 inches. Using a significance level of = 0.05, test the appropriate hypotheses. Find the p-value for the test.

Test statistic =

p-value =

Conclusion:

Interpretation: ANSWER:

-1.00; 0.3174; Do not reject H0; Pipes of the proper size are being produced

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:23 AM DATE MODIFIED: 2/4/2019 9:23 AM 100. If we reject the null hypothesis

the 0.05 level.

at the 0.01 level of significance, then we must also reject it at

Chapter 09 - Large-Sample Tests of Hypotheses a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 101. In testing the difference between two population means using two independent samples, we use the pooled

variance in estimating the standard error of the sampling distribution of the sample mean difference populations are normal with equal variances.

if the

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 102. The z-test can be used to determine whether two population means are equal. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 103. In estimating the difference between two population means, if a 90% confidence interval includes zero,

then we can be 90% certain that the difference between the two population means is zero. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 104. Increasing the size of the samples in a study to estimate the difference between two population means will

increase the probability of committing a Type I error that a decision maker can have regarding the interval

Chapter 09 - Large-Sample Tests of Hypotheses

estimate. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 105. In estimating the difference between two population means, the estimate for the standard deviation of the

sampling distribution of

is found by taking the square root of the sum of the two sample variances.

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 106. With all other factors held constant, increasing the confidence level for a confidence interval estimate for

the difference between two population means will result in a wider confidence interval estimate. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 107. In estimating the difference between two population means, the following summary statistics were found:

and a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM

Based on these results, the point estimate of

is .70.

Chapter 09 - Large-Sample Tests of Hypotheses 108. The significance level in a hypothesis test for the difference between two population means is the same as

the probability of committing a Type I error. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 109. If you wish to test whether two populations means are the same, the appropriate null and alternative

hypotheses would be:

vs.

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 110. Independent samples are those for which the selection process for one is not related to the selection process

for the other. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 111. In testing the difference between two population means using two independent samples, the sampling a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM

Chapter 09 - Large-Sample Tests of Hypotheses

distribution of the sample mean difference

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM

is normal if the sample sizes are both greater than 30.

Chapter 09 - Large-Sample Tests of Hypotheses 112. A political analyst in Iowa surveys a random sample of registered Democrats and compares the results with

those obtained from a random sample of registered Republicans. This would be an example of two independent samples. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 113. In testing the difference between two population means using two independent samples, the population

standard deviations are assumed to be known, and the calculated test statistic equals 2.75. If the test is two-tail and 5% level of significance has been specified, the conclusion should be not to reject the null hypothesis. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 114. The sampling distribution of

is normal if the sampled populations are normal, and approximately normal if the populations are nonnormal and the sample sizes and are large. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 115. The expected value of a. True

is E (

b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM

Chapter 09 - Large-Sample Tests of Hypotheses DATE MODIFIED: 2/4/2019 9:24 AM

Chapter 09 - Large-Sample Tests of Hypotheses

116. The variance of

is V (

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 117. When we test for differences between the means of two independent populations, we can only use a two-

tailed test. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 118. When testing for differences between the means of two dependent populations, we can use either a one-

tailed or two-tailed test. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 119. Suppose that we reject the null hypothesis

at the 0 .05 level of significance. Then for which of the following -values do we also reject the null hypothesis? a. 0.02 b. 0.04 c. 0.06 d. 0.01 e. All of these. ANSWER:

Chapter 09 - Large-Sample Tests of Hypotheses POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 4/5/2019 4:56 AM 120. If you wish to construct a confidence interval estimate for the difference between two population means, an

increase in the sample sizes used will result in: a. a decrease in the critical value z b. a narrower confidence interval c. a wider confidence interval d. a confidence interval that contains zero e. a confidence interval that does not contain zero ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 121. If you wish to estimate the difference between two population means using two independent large samples,

the 90% confidence interval estimate can be constructed using which of the following critical values? a. 1.96 b. 2.33 c. 2.58 d. 1.645 e. 1.28 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 122. In testing

, the test statistic value z is found to be 1.69. What is the p-value of

the test? a. 0455 b. 0910 c. 1977 d. 3023 e. 3478 ANSWER: POINTS:

a 1

Chapter 09 - Large-Sample Tests of Hypotheses QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 123. Two independent samples of sizes 40 and 50 are randomly selected from two populations to test the

difference between the population means

. The sampling distribution of the sample mean difference

is: a. normally distributed b. approximately normal c. Student t-distributed with 88 degrees of freedom d. approximately normal and student t-distributed with 88 degrees of freedom e. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 124. In testing the difference between two population means using two independent samples, the sampling

distribution of the sample mean difference is normal if: a. the sample sizes are both greater than 30 b. the populations are normal c. the populations are non-normal and the sample sizes are large d. all of these e. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM

, the observed value of the z-score was found to be –2.15. The

125. When testing

p-value for this test would be: a. 0158 b. 0316 c. 1582 d. 9842 e. 9684 ANSWER:

Chapter 09 - Large-Sample Tests of Hypotheses POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 126. In testing the difference between two population means using two independent samples, the population

standard deviations are assumed to be known and the calculated test statistic equals 2.56. If the test is two-tail and 5% level of significance has been specified, the conclusion should be to: a. reject the null hypothesis b. not to reject the null hypothesis c. repeat using a one-tail test d. choose two other independent samples e. none of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM

, the observed value of the z-score was found to be –2.15.

127. When testing

Then, the p-value for this test would be: a. 0136 b. 0158 c. 0316 d. 9864 e. 0.9842 ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 128. In testing for differences between the means of two independent populations the null hypothesis is: a. b. c. d. e. ANSWER: POINTS:

b 1

Chapter 09 - Large-Sample Tests of Hypotheses QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 129. When testing

, the observed value of the z-score was found to be –2.15.

Then, the p-value for this test would be a. .0158 b. .0316 c. .9842 d. .9864 e. .9964 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 130. When the necessary conditions are met, a two-tailed test is being conducted to test the difference between

two population means, but your statistical software provides only a one-tail area of .036 as part of its output. The p-value for this test will be: a. 0.018 b. 0.009 c. 0.072 d. 0.928 e. 0.964 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 131. An airline company would like to know if the average number of passengers on a flight in November is less

than the average number of passengers on a flight in December. The results of random sampling are printed below.

Test the appropriate hypotheses using = 0.01. Test statistic =

Chapter 09 - Large-Sample Tests of Hypotheses

Critical Value(s) = Conclusion: Interpretation: ANSWER:

-4.61; -2.33; Reject H0; The average number of passengers is significantly less on a November flight

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 4/5/2019 6:00 AM 132. A university investigation was conducted to determine whether women and men complete medical school

in significantly different amounts of time, on the average. Two independent random samples were selected and the following summary information concerning times to completion of medical school computed:

Perform the appropriate test of hypothesis to determine whether there is a significant difference in time to completion of medical school between women and men. Test using = 0.05. Round your answer for the test statistic to two decimal places. Test statistic = Critical Value(s) = Conclusion: Interpretation: Find the p-value associated with the test above. p-value = ANSWER:

-1.24; 1.96, -1.96; Do not reject H0; There is NO difference in mean time to completion between women and men; 0.2150

POINTS: QUESTION TYPE: HAS VARIABLES:

1 Subjective Short Answer False

Chapter 09 - Large-Sample Tests of Hypotheses STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 4/5/2019 5:27 AM 133. A social worker was interested in determining whether there is a significant difference in the average

monthly cost per child for childcare outside the home between state supported facilities and privately owned facilities. Two independent random samples yielded the following information:

Perform the appropriate test of hypothesis to determine whether there is a significant difference in the average monthly cost per child for childcare between the two types of facilities. Use = 0.10. Round your answer for the test statistic to two decimal places. Test statistic = Critical Value(s) = Conclusion: Interpretation: Find the p-value for the test above. p-value = ANSWER:

1.93; 1.645, -1.645; Reject H0; There is a significant difference in average monthly cost; 0.0536

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 4/5/2019 5:28 AM 134. A computer laboratory manager was in charge of purchasing new battery packs for her lab of laptop

computers. She narrowed her choices to two models that were available for her machines. Since the models cost about the same, she was interested in determining whether there was a difference in the average time the battery packs would function before needing to be recharged. She took two independent samples and computed the following summary information:

Chapter 09 - Large-Sample Tests of Hypotheses

Perform the appropriate test of hypothesis to determine whether there is a significant difference in average functioning time before recharging between the two models of battery packs. Test using = 0.10. Test statistic = Critical Value(s) = Conclusion: Interpretation: Find the p-value for the test above. p-value = ANSWER:

-1.82; 1.645, -1.645; Reject H0; There is a significant difference in average functioning time; 0.0688

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 4/5/2019 5:26 AM 135. Independent random samples of 36 and 50 observations are drawn from two quantitative populations, 1 and

2, respectively. The sample data summary is shown here:

Do the data present sufficient evidence to indicate that the mean for population 1 is smaller than the mean for population 2? Test using = 0.05. Test statistic = Critical Value(s) = Conclusion:

Chapter 09 - Large-Sample Tests of Hypotheses

Interpretation: Find the p-value for the test above. p-value = ANSWER:

-1.34; -1.645; Do not reject H0; The mean of population 1 is NOT smaller than the mean of population 2; 0.0901

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 4/5/2019 5:55 AM 136. To test the theory that the consumption of red meat in the United States has decreased over the last 10

years, a researcher decides to select hospital nutrition records for 400 subjects surveyed 10 years ago and to compare their average amount of beef consumed per year to amounts consumed by an equal number of subjects interviewed this year. The data are given in the table.

Do the data present sufficient evidence to indicate that per-capita beef consumption has decreased in the last 10 years? Test at the 1% level of significance. Test statistic = Critical Value(s) = Conclusion: Interpretation: Find a 99% lower confidence bound for the difference in the average per-capita beef consumption for the two groups.

Does your confidence bound confirm your conclusions above?

Explain.

Chapter 09 - Large-Sample Tests of Hypotheses

What additional information does the confidence bound give you?

ANSWER:

3.35; 2.33; Reject H0; The average per-capita beef consumption has decreased in the last ten years; 2.13; Yes; Since the difference in the mean is positive, you can again conclude that there has been a decrease in the average per-capita beef consumption over the last ten years.; In addition, it is likely that the average consumption has decreased by more than 5.63 pounds per year.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 4/5/2019 5:53 AM 137. In an attempt to compare the starting salaries for college graduates who majored in business and the

education, random samples of 50 recent college graduates in each major were selected and the following information was obtained:

Do the data provide sufficient evidence to indicate a difference in average starting salaries for college graduates who majored in business and education? Test using = 0.05.

Test statistic =

Critical Value(s) =

Conclusion:

Interpretation: ANSWER:

5.02; 1.96, -1.96; Reject H0; There is a difference in the means

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:24 AM

Chapter 09 - Large-Sample Tests of Hypotheses DATE MODIFIED:

2/4/2019 9:24 AM

138. An insurance company wants to test the hypothesis that the mean amount of life insurance held by

professional men equals that held by professional women. Accordingly, two independent simple random samples are taken from appropriate professional listings of men and women. The sample of 200 men reveals a mean amount of $140,000 with a standard deviation $26,000. The sample of 400 women shows a mean amount of $128,000 with a standard deviation of $3,000. Test the hypothesis using a 0.05 significance level.

Test statistic =

p-value =

Critical Value(s) =

Conclusion:

Interpretation: Construct 95% confidence interval for the difference in mean amount of life insurance held by professional men and women.

Explain how to use the 95% confidence interval to test the appropriate hypotheses at = 0.05.

ANSWER:

6.51; 0.00; -1.96, 1.96; Reject H0; Men's and women's life insurance policies are NOT equal; (8384.61, 15615.39); Since the hypothesized difference 0 is not contained in the confidence interval, H0 should be rejected.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 139. The proportion of defective computers built by Byte Computer Corporation is 0.15. In an attempt to lower

the defective rate, the owner ordered some changes made in the assembly process. After the changes were put

Chapter 09 - Large-Sample Tests of Hypotheses

into effect, a random sample of 42 computers were tested revealing a total of 4 defective computers. Perform the appropriate test of hypothesis to determine whether the proportion of defective computer has been lowered. Use = 0.01. Do not round the intermediate calculations. Test statistic = Critical Value(s) = Conclusion: Interpretation: ANSWER:

-0.994; -2.33; Do not reject H0; The proportion of defective computers has NOT been lowered

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 4/8/2019 11:58 PM 140. A gas company president for a particular city is interested in the proportion of homes heated by gas.

Historically, the proportion of homes heated by gas has been 0.65. A sample of 75 home was selected and it was found that 44 of them heat with gas. Perform the appropriate test of hypothesis to determine whether the proportion of home heated by gas has changed. Test using = 0.05. Test statistic = Critical Value(s) = Conclusion: Interpretation: Find the p-value for this test. p-value = ANSWER:

-1.15; 1.96, -1.96; Do not reject H0; The proportion of homes heated by gas has NOT changed; 0.2502

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic

Chapter 09 - Large-Sample Tests of Hypotheses DATE CREATED: DATE MODIFIED:

2/4/2019 9:24 AM 4/5/2019 6:16 AM

141.141. ANSWER:

3.42; 2.58; reject H0; Yes, the marina owner is correct

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 4/5/2019 6:30 AM 142. A student government representative at a local university claims that 60% of the undergraduate students

favor a move to Division I in college football. A random sample of 250 undergraduate students was selected and 140 students indicated they favored a move to Division I. Perform the appropriate test of hypothesis to test the representative's claim. Use = 0.05. Round your answer for the test statistic to two decimal plaecs. Test statistic = Critical Value(s) = Conclusion: Interpretation: Find the p-value for this test. p-value = ANSWER:

-1.29; -1.96, 1.96; Do not reject H0; The proportion of undergraduate student who favor a move is 0.60; 0.1970

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 4/5/2019 6:28 AM 143. A random sample of 150 observations was selected from a binomial population, and 87 successes were

observed. Do the data provide sufficient evidence to indicate that the population proportion p is greater than 0.5? Use the critical value approach and the p-value approach, and test at = 0.05.

Test statistic =

Chapter 09 - Large-Sample Tests of Hypotheses

p-value =

Critical Value(s) =

Conclusion:

Interpretation: ANSWER:

1.96; 0.025; 1.645; Reject H0; The proportion is greater than 0.5

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 144. A peony plant with red petals was crossed with another plant having streaky petals. A geneticist states that

80% of the offspring resulting from this cross will have red flowers. To test this claim, 120 seeds from this cross were collected and germinated and 84 plants had red petals. Calculate the test statistic and its observed significance level (p-value). Use the p-value to evaluate the statistical significance of the results at the 1% level.

p-value =

Conclusion:

Interpretation: ANSWER:

0.0062; Reject H0; The proportion of red flowered plants is NOT 0.80

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 145. A marketing manager wants to test the hypothesis that 90% of tennis magazine's subscribers live in their

own homes. Accordingly, a simple random sample of 80 is taken from the magazine's list of subscribers. The sample turns out to contain 64 homeowners. Use a significance level of = .05.

Chapter 09 - Large-Sample Tests of Hypotheses

Test statistic =

p-value =

Conclusion:

Interpretation: ANSWER:

-2.98; 0.0028; Reject H0; The percentage of subscribes who live in their own homes is NOT 90%

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 146. A union composed of several thousand employees is preparing to vote on a new contract. A random sample

of 500 employees yielded 320 who planned to vote yes. It is believed that the new contract will receive more than 60% yes votes. Can we infer at the 5% significance level that the new contract will receive more than 60% yes votes?

Test statistic =

p-value =

Conclusion:

Interpretation: ANSWER:

1.83; 0.0336; Reject H0; The new contract will receive more than 60% yes votes

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 147. A professor claims that 70% of College of Business graduates earn more than $45,000 per year. In a

random sample of 300 graduates, 195 earn more than $45,000. Can we reject the professor's claim at the 5% significance level?

Chapter 09 - Large-Sample Tests of Hypotheses

Test statistic =

p-value =

Conclusion:

Interpretation: ANSWER:

-1.89; 0.0294; Do not reject H0; We CANNOT reject the professor's claim

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 148. In clinical studies of an allergy drug, 81 of the 900 subjects experienced drowsiness. A competitor claims

that 10% of the users of this drug experience drowsiness. Is there enough evidence at the 5% significance level to infer that the competitor is correct?

Test statistic =

p-value =

Conclusion:

Interpretation: Construct a 95% confidence interval estimate of the population proportion of the users of this allergy drug who experience drowsiness.

Explain how to use this confidence interval to test the hypotheses.

ANSWER:

-1.0; 0.3174; Do not reject H0; The competitor is correct; (0.071, 0.109); Since the

Chapter 09 - Large-Sample Tests of Hypotheses

hypothesized value 0.10 is included in this 95% confidence interval, we fail to reject H0 at alpha = 0.05. POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 149. If the null hypothesis

is rejected at the 0.05 level of significance, it must be rejected at the 0.01

level. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 150. In testing

vs.

, any p-value greater than .025 will lead to a rejection of the null

hypothesis. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 151. A one-tailed hypothesis test of the population proportion is used when the alternative hypothesis takes the

form

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 152. In testing

vs.

the level of significance must be twice as large as when testing

Chapter 09 - Large-Sample Tests of Hypotheses

vs.

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 153. A two-tailed hypothesis test of the population proportion takes the form a. True

vs.

b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 154. The campaign manager of John Kerry believes that more than 52% of the registered voters will vote in

favor of Kerry. If you wish to test this claim, the appropriate null and alternative hypotheses are .

vs.

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 155. When the hypothesized proportion

proportion

is close to 0.50, the spread in the sampling distribution of the sample

is greater than when is close to 0.0 or 1.0.

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 4/23/2019 5:58 AM

Chapter 09 - Large-Sample Tests of Hypotheses

156. When testing

vs. , an increase in the sample size will result in a decrease in the probability of committing a Type I error. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 157. In testing

vs. a random sample of size 100 produced a sample proportion these results, the test statistic value is z = -.655.

Given

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 158. In testing

vs. test would be approximately .1151.

the test statistic value is found to be equal to 1.20. The p-value for this

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 159. In testing

vs.

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM

a random sample of size 200 produced a sample proportion

Chapter 09 - Large-Sample Tests of Hypotheses

Given these results, the null hypothesis should not be rejected at = .05.

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM

Chapter 09 - Large-Sample Tests of Hypotheses DATE MODIFIED: 2/4/2019 9:24 AM 160. Suppose in testing a hypothesis about a proportion, the p-value is computed to be 0.027. The null

hypothesis should be rejected if the chosen level of significance is 0.01. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 161. The lower limit of the 90% confidence interval for the population proportion p, given that n = 400 and

0.10 is 0.1247. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 162. If a null hypothesis about the population proportion p is rejected at the 0.10 level of significance, it must be

rejected at the 0.05 level. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 163. In a one-tail test about the population proportion p, the p-value is found to be equal to 0.0352. If the test a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM

Chapter 09 - Large-Sample Tests of Hypotheses DATE MODIFIED: 2/5/2019 9:24 AM

had been two-tailed, the p-value would have been 0.0704.

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM

Chapter 09 - Large-Sample Tests of Hypotheses DATE MODIFIED: 4/6/2019 7:03 AM 164. A professor of statistics refutes the claim that the proportion of Republican voters in Michigan is at most

44%. To test the claim, the hypotheses:

, should be used.

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 165. In testing a hypothesis about a population proportion p, the z test statistic measures how close the computed

sample proportion

has come to the hypothesized population parameter.

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 166. In a two-tailed test for the population proportion, if the null hypothesis is rejected when the alternative

hypothesis is false, a Type I error is committed. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 4/5/2019 7:04 AM 167. In a one-tailed test for the population proportion, if the null hypothesis is not rejected when the alternative

hypothesis is false, a Type II error is committed. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM

Chapter 09 - Large-Sample Tests of Hypotheses DATE MODIFIED: 4/5/2019 7:04 AM 168. The sampling distribution of

is approximately normal, provided that the sample size is large enough (n >

30). a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 169. Suppose in testing a hypothesis about a proportion, the p-value is computed to be 0.038. The null

hypothesis should be rejected if the chosen level of significance is 0.05. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 170. For a given data set and confidence level, the confidence interval of the population proportion p will be

wider for 95% confidence than for 90% confidence. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 171. A two-tailed test of the population proportion produces a test statistic z = 1.77. The p-value of the test is a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM

Chapter 09 - Large-Sample Tests of Hypotheses DATE MODIFIED: 4/5/2019 7:04 AM

0.4616.

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM

Chapter 09 - Large-Sample Tests of Hypotheses DATE MODIFIED: 2/4/2019 9:24 AM 172. The upper limit of the 85% confidence interval for the population proportion p, given that n = 60 and

0.20 is 0.274. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 173. Suppose in testing a hypothesis about a proportion, the z test statistic is computed to be 1.92. The null

hypothesis should be rejected if the chosen level of significance is 0.01 and a two-tailed test is used. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 174. The rejection region for testing

at the 0.05 level of significance is:

a. |z| < 1.28 b. |z| > 1.96 c. z > 1.645 d. z < 2.33 e. z < 2.58 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 175. In a hypothesis test involving the population proportion, which of the following would be an acceptable

formulation? a.

vs.

Chapter 09 - Large-Sample Tests of Hypotheses c.

vs.

d. vs.

and e. none of these

vs.

areacceptable

ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 4/5/2019 7:11 AM 176. In testing

vs. random sample of size 200 produced a sample proportion these results, the p-value of the test is approximately: a. 4616 b. 5384 c. 0384 d. 0768 e. 2812

Given

ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 177. In selecting the sample size to estimate the population proportion p, if we have no knowledge of even the

approximate values of the sample proportion

, we:

a. take another sample and estimate b. take two more samples and find the average of their c. let d. let e. let

=0.50 =0.95 =0.05

ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 178. The use of the standard normal distribution for constructing confidence interval estimate for the population

Chapter 09 - Large-Sample Tests of Hypotheses

proportion p requires: a. and are both greater than 5, where b. np and n(1 - p) are both greater than 5 c. n(p + ) and n(p - ) are both greater than 5 d. that the sample size is greater than 5 e. that the sample size is greater than 10

denotes the sample proportion

ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 179. The lower limit of a confidence interval at the 95% level of confidence for the population proportion if a

sample of size 200 had 40 successes is: a. 0.2554 b. 0.1446 c. 0.2465 d. 0.1535 e. 0.3390 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 180. Assuming that all necessary conditions are met, what needs to be changed in the formula

, so that we can use it to construct a confidence interval estimate for the population proportion p? a. The should be replaced by p. b. The should be replaced by . c. The should be replaced by . d. The should be replaced by . e. The should be replaced by . ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM

Chapter 09 - Large-Sample Tests of Hypotheses 181. From a sample of 400 items, 14 are found to be defective. The point estimate of the population proportion

defective will be: a. 14 b. 0.035 c. 28.57 d. 0.05 e. 0.26 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 182. After calculating the sample size needed to estimate a population proportion to within 0.04, your statistics

professor told you the maximum allowable error must be reduced to just .01. If the original calculation led to a sample size of 800, the sample size will now have to be: a. 800 b. 3200 c. 12,800 d. 6400 e. 1600 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 183. The width of a confidence interval estimate for a proportion will be: a. narrower for 99% confidence than for 95% confidence b. wider for a sample size of 100 than for a sample size of 50 c. narrower for 90% confidence than for 95% confidence d. narrower when the sample proportion if 0.50 than when the sample proportion is 0.20 e. none of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM

Chapter 09 - Large-Sample Tests of Hypotheses 184. Which of the following would be an appropriate null hypothesis? a. The population proportion is equal to 0.60. b. The sample proportion is equal to 0.60. c. The population proportion is not equal to 0.60. d. The population proportion is greater than 0.60. e. All of these. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 185. Which of the following would be an appropriate alternative hypothesis? a. The population proportion is less than 0.65. b. The sample proportion is less than 0.65. c. The population proportion is equal to 0.65. d. The sample proportion is equal to 0.65. e. The population proportion is less than 0.65 and the sample proportion is equal to 0.65. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 186. A survey claims that 9 out of 10 doctors recommend aspirin for their patients with headaches. To test this

claim against the alternative that the actual proportion of doctors who recommend aspirin is less than 0.90, a random sample of 100 doctors' results in 83 who indicate that they recommend aspirin. The value of the test statistic in this problem is approximately equal to: a. -1.67 b. -2.33 c. -1.86 d. -0.14 e. -2.58 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 187. If we reject the null hypothesis

, we conclude that there is not enough statistical evidence to

Chapter 09 - Large-Sample Tests of Hypotheses

infer that the population proportions are equal. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 188. When the necessary conditions are met, a two-tailed test is being conducted to test the difference between

two population proportions. The two sample proportions are and , and the standard error of the sampling distribution of is 0.0085. The calculated value of the test statistic will be z = 3.41. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 4/23/2019 6:14 AM 189. In testing

vs. used to conduct the test is z = 1.645.

using a significance level equal to .05, the critical value that will be

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 190. In testing

vs.

approximately .1003. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM

the test statistic value is found to be z = 1.28. The p-value of the test is

Chapter 09 - Large-Sample Tests of Hypotheses DATE MODIFIED: 2/4/2019 9:24 AM

191. The test statistic that is used in testing

vs.

where

. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 192. In testing

and

vs.

the following summary statistics are found:

n2=100

Based on these results, the null hypothesis should be rejected at the significance level

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 4/5/2019 7:20 AM 193. When the necessary conditions are met, a two-tailed test is being conducted to test the difference between

two population proportions. The two sample proportions are standard error of the sampling distribution of be 1.50.

and

, respectively, and the

is 0.04. Then, the calculated value of the test statistic will

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 194. When the necessary conditions are met, a two-tailed test is being conducted for the difference between two

Chapter 09 - Large-Sample Tests of Hypotheses

population proportions. If the value of the test statistic is –1.35, then the p-value is 0.0885. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 4/23/2019 6:31 AM 195. When the necessary conditions are met, a two-tailed test is being conducted for the difference between two

population proportions. If the value of the test statistic is 1.96, then the null hypothesis is rejected at = 0.10. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 196. When the necessary conditions are met, an upper tailed test is being conducted for the difference between

two population proportions. If the value of the test statistic is 2.90, then the p-value is 0.0038. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 197.When the necessary conditions are met, a lower tailed test is being conducted for the difference between

two population proportions. If the value of the test statistic is -2.43, then the null hypothesis cannot be rejected at = 0.025. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 198. When the necessary conditions are met, a lower tailed test is being conducted for the difference between

Chapter 09 - Large-Sample Tests of Hypotheses

two population proportions. If the value of the test statistic is -2.50, then the p-value is 0.0062. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 199. In constructing a confidence interval estimate for the difference between two population proportions, we: a. pool the population proportions when the populations are normally distributed b. pool the population proportions when the population means are equal c. pool the population proportions when they are equal d. never pool the population proportions to construct confidence interval for e. always pool the population proportions to construct confidence interval for ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 200. A sample of size 100 selected from one population has 60 successes, and a sample of size 150 selected

from a second population has 95 successes. The test statistic for testing the equality of the population proportions equal to: a. -0.5319 b. 0.7293 c. -0.419 d. 0.2702 e. -0.3518 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 201. For testing the difference between two population proportions, the pooled proportion estimate should be

used to compute the value of the test statistic when the: a. populations are normally distributed b. sample sizes are small c. samples are independently drawn from the populations

Chapter 09 - Large-Sample Tests of Hypotheses d. null hypothesis states that the two population proportions are equal e. populations are normally distributed and sample sizes are small ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 202. In testing the null hypothesis

, if

is false, the test could lead to:

a. a Type I error b. a Type II error c. a Type O error d. either a Type I or a Type II error e. neither a Type I nor a Type II error ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 203. Which of the following is a required condition for using the normal approximation to the binomial in

testing the difference between two population proportions? a.

and

ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 4/23/2019 7:04 AM 204. A sample of size 150 from population 1 has 40 successes. A sample of size 250 from population 2 has 30

successes. The value of the test statistic for testing the null hypothesis that the proportion of successes in population one exceeds the proportion of successes in population two by 0.05 is:

Chapter 09 - Large-Sample Tests of Hypotheses a. 1.645 b. 2.327 c. 1.960 d. 1.977 e. 1.772 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 205. When the necessary conditions are met, a two-tail test is being conducted to test the difference between two

population proportions. If the value of the test statistic is 2.05, then the p-value is: a. 0.4798 b. 0.0404 c. 0.2399 d. 0.0202 e. 0.1982 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM 206. When the necessary conditions are met, a two-tail test is being conducted to test the difference between two

population proportions. The two sample proportions are sampling distribution of

and

, and the standard error of the

is 0.04. The calculated value of the test statistic will be:

a. z = 0.25 b. z = 1.25 c. t = 0.25 d. t = 0.80 e. t = 1.25 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 4/24/2019 2:07 AM 207. A group in favor of freezing production of nuclear weapons believes that the proportion of individuals in

Chapter 09 - Large-Sample Tests of Hypotheses

favor of a nuclear freeze is greater for those who have seen the movie "The Day After" (population 1) than those who have not (population 2). In an attempt to verify this belief, random samples of size 500 are obtained from the populations of interest. Among those who had seen "The Day After", 228 were in favor of a freeze. For those who had not seen the movie, 196 favored a freeze. Test using = 0.05. Test statistic = Critical Value(s) = Conclusion: Interpretation: ANSWER:

2.048; 1.645; Reject H0; The proportion in favor of a freeze is greater in population 1

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 4/5/2019 7:32 AM 208. The Environmental Protection Agency wanted to compare the proportion of plants in violation of air

quality standards for two different industries: steel and utility. Two independent samples of plants were selected and monitored. The following data was recorded:

Test at = 0.01 Test statistic = Critical Value(s) = Conclusion: Interpretation: ANSWER:

0.1645; 2.58, -2.58; Do not reject H0; There is NO difference in the proportion of violations between the two industries

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:24 AM

Chapter 09 - Large-Sample Tests of Hypotheses DATE MODIFIED:

4/5/2019 7:35 AM

209. A manufacturing plant has two assembly lines for producing plastic bottles. The plant manager was

concerned about whether the proportion of defective bottles differed between the two lines. Two independent random samples were selected and the following summary data computed:

Perform the appropriate test of hypothesis using = 0.05. Test statistic = Critical Value(s) = Conclusion: Interpretation: ANSWER:

-0.32; 1.96, -1.96; Do not reject H0; There is NO difference between the two assembly lines

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 4/5/2019 7:37 AM 210. Independent random samples of n1 = 150 and n2 = 150 sales phone calls for an insurance policy were

randomly selected from binomial populations 1 and 2, respectively. Sample 1 had 80 successful sales, and sample 2 had 88 successful sales. Suppose you have no preconceived theory concerning which parameter, p1 or p2, is the larger and you wish to detect only a difference between the two parameters if one exists. Calculate the standard error of the difference in the two sample proportions, pooled estimate for the common value of p.

. Make sure to use the

Calculate the test statistic that you would use for the test above. Based on your knowledge of the standard normal distribution, is this a likely or unlikely observation, assuming that H0 is true and the two population proportions are the same? Test statistic =

Chapter 09 - Large-Sample Tests of Hypotheses

Find the p-value for the test. Test for a significant difference in the population means at the 1% significance level. p-value = Find the rejection region when = 0.01. Do the data provide sufficient evidence to indicate a difference in the population proportions? Critical Value(s) = Conclusion: Interpretation: ANSWER:

0.0573; -0.94; 0.3472; 2.58, -2.58; Do not reject H0; There is NO evidence of a difference in the two population proportions

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 4/5/2019 7:39 AM 211. An experiment was conducted to test the effect of a new drug on a viral infection. The infection was

induced in 100 mice, and the mice were randomly split into two groups of 50. The first group, the control group, received no treatment for the infection. The second group received the drug. The proportions of survivors,

and

, in the two groups after a 30-day period, were found to be 0.40 and 0.64, respectively. Is

there sufficient evidence to indicate that the drug is effective in treating the viral infection? Use = 0.05. Test statistic = Critical Value(s) = Conclusion: Interpretation: Use a 95% confidence interval to estimate the actual difference in the cure rates for the treated versus the control groups.

ANSWER:

-2.40; -1.645; Reject H0; There is evidence of a difference in the two groups; (0.430, -0.050)

POINTS:

Chapter 09 - Large-Sample Tests of Hypotheses QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 4/10/2019 2:39 AM 212. A cable company in Michigan is thinking of offering its service in one of two counties; Mecosta and

Newaygo. Allegedly, the proportion of households in either county ready to hook up to the cable is the same, but the company wants to test the claim. Accordingly, it takes a simple random sample in each county. In Mecosta county, 175 of 200 households say they will join. In Newaygo county, 665 of 800 households say so. Calculate the pooled estimate of the common proportion p.

Calculate the standard error of

Calculate the value of the test statistic.

Calculate the p-value and write your conclusion given that = 0.05.

Conclusion: Interpretation: Construct 95% confidence interval for the difference in proportions of households in Mecosta and Newaygo counties who are ready to hook up to the cable.

Explain how to use the 95% confidence interval to test the appropriate hypotheses at = 0.05.

ANSWER:

0.84; 0.02898; 1.51; 0.131; Do not reject H0; The proportions of households are the same; (-0.00892, 0.09642); Since the hypothesized difference 0 is included in the confidence interval, H0 should not be rejected.

POINTS: QUESTION TYPE: HAS VARIABLES:

1 Subjective Short Answer False

Chapter 09 - Large-Sample Tests of Hypotheses STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 4/9/2019 12:52 AM 213. In testing the hypotheses

H0: p1 - p2 = 0 vs. Ha: p1 - p2 ≠ 0. Use the following statistics, where x1 and x2 represent the number of Dial Soap sales in the two samples, respectively. n1 = 150, x1 = 72 n2 = 175, x2 = 70 What conclusion can we draw at the 5% significance level? Test statistic = Critical Value(s) = Conclusion: What is the p-value of the test? p-value = Explain how to use the p-value to test the hypotheses.

Estimate with 95% confidence the difference between the two population proportions.

Interpret and explain how to use the confidence interval to test the hypotheses.

ANSWER:

1.449; 1.96, -1.96; Do not reject H0; 0.147; Since p-value = 0.147 > 0.05, we fail to reject the null hypothesis; (-0.028, 0.188); We estimate that the difference between the population proportions lies between -0.028 and 0.188. Since the hypothesized value 0 is included in the 95% interval estimate, we fail to reject the null hypothesis at 0.05.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic

Chapter 09 - Large-Sample Tests of Hypotheses DATE CREATED: DATE MODIFIED:

2/4/2019 9:24 AM 4/9/2019 1:03 AM

214. In testing the hypotheses H0: p1 - p2 = 0 vs. Ha: p1 - p2 > 0, use the following statistics, where x1 and x2

represent the number of defective components found in medical instruments in the two samples. n1 = 200, x1 = 80 n2 = 400, x2 = 140 What conclusion can we draw at the 5% significance level?

Test statistic =

Critical Value(s) =

Conclusion: What is the p-value of the test?

p-value = Explain how to use the p-value to test the hypotheses.

Estimate with 95% confidence the difference between the two population proportions.

ANSWER:

1.198; 1.645; Do not reject H0; 0.1151; Since the p-value = 0.1151 > 0.05, we fail to reject the null hypothesis; (-0.0324, 0.1324)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:24 AM DATE MODIFIED: 2/4/2019 9:24 AM

Chapter 10 - Inference from Small Samples 1. In making inferences about a population mean , the degrees of freedom used in t distribution are equal to the

sample size. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 6:01 AM 2. Regardless of the degrees of freedom, every t distribution is symmetric around zero. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 6:03 AM 3. The "shape" of the t distribution changes as the value of the sample mean changes. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 6:07 AM 4. If a sample of size 15 is randomly selected from a population, the value of A for the probability P(t A) = 0.01

is 2.602. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 5. If a sample of size 20 is randomly selected from a population, the value of A for the probability P(−A t A) =

0.95 is 2.093.

Chapter 10 - Inference from Small Samples a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 9:01 AM 6. If a sample has 15 observations and a 95% confidence estimate for need to be constructed, the appropriate t-

score is 2.131. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 7. If a sample has 10 observations and a 90% confidence estimate for is needed, the appropriate t-score is

1.833. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 8. Student's t distribution is a sampling distribution for a random variable, t, derived from a normally distributed

population, that is (1) single-peaked above the random variable's mean, median, and mode of zero, (2) perfectly symmetrical about this central value, and (3) characterized by tails extending indefinitely in both directions from the center, approaching, but never touching, the horizontal axis. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 6:18 AM 9. With all other factors held constant, confidence intervals constructed with small samples tend to have greater

Chapter 10 - Inference from Small Samples

margin of error than those constructed from larger samples. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 10. A random sample of size 10 produced a sample mean equal to 12 and a standard deviation equal to

.15. Assume the sample was taken from a normally distributed population. Based on this information, the upper limit for a 95% confidence interval estimate is approximately 12.107. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 6:38 AM 11. A random sample of size 10 produced a sample mean equal to 12 and a standard deviation equal to .15.

Assume the sample was taken from a normally distributed population. Based on this information, the margin of error associated with a 90% confidence interval estimate for the population mean is 1.8331. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 6:37 AM 12. The t distribution is used to construct confidence interval for the population mean when the population is

unknown and the sample size is small. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 6:41 AM

Chapter 10 - Inference from Small Samples 13. A random sample of size 9 produced a sample mean equal to 13.5 and a standard deviation of 3.2. Assume

the sample was taken from a normal population. The margin of error associated with a 95% confidence interval estimate for the population mean is approximately 2.46. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 6:46 AM 14. A 90% confidence interval estimate for the population mean constructed with a small sample will have a

margin of error that is approximately 90% of the population size n. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 15. If a sample has 15 observations and a 90% confidence estimate for is needed, the appropriate t-score is

1.341. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 16. If a sample has 18 observations and a 90% confidence estimate for is needed, the appropriate t-score is

1.740. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM

Chapter 10 - Inference from Small Samples 17. The statistic

) when the sampled population is normal follows the Student's t distribution with

n degrees of freedom. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 9:15 AM 18. The t distribution approaches the normal distribution as the number of degrees of freedom increases. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 6:58 AM 19. In order to determine the p-value associated with hypothesis testing about the population mean , it is

necessary to know the value of the test statistic. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 20. Statisticians have shown that the mathematical process that derived the Student t distribution is robust,

which means that if the sampled population is nonnormal, the t-test of the population mean is still valid, provided that the population is not extremely nonnormal. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM

Chapter 10 - Inference from Small Samples 21. A race car driver tested his car for time from 0 to 60 mph, and in 20 tests obtained an average of 4.85

seconds with a standard deviation of 1.47 seconds. A 95% confidence interval for the 0 to 60 time is 4.52 seconds to 5.18 seconds. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/2/2019 7:55 AM 22. In forming a 95% confidence interval for a population mean from a sample size of 20, the number of degrees

of freedom from the t distribution equals 18. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 7:10 AM 23. The t distribution allows the calculation of confidence intervals for means when the actual standard error is

not known. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 7:12 AM 24. The t distribution allows the calculation of confidence intervals for means for small samples when the

population variance is not known, regardless of the shape of the distribution in the population. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 7:13 AM

Chapter 10 - Inference from Small Samples 25. For a t distribution with 12 degrees of freedom, the area between -2.6810 and 2.1788 is 0.980. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 7:14 AM 26. When finding a confidence interval for a population mean based on a sample of size 8, which assumption is

made? a. The population standard deviation, is known. b. The sampling distribution of z is normal. c. The sampled population is approximately normal. d. There is no special assumption made. e. None of these. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 27. As the degrees of freedom for the t distribution increase, the distribution approaches the: a. chi-square distribution b. F distribution c. z distribution d. normal distribution with μ = 0 and σ2 = 0.5 e. none of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 7:47 AM 28. The sampling distribution of the statistic

from: a. Student t distribution b. a normal distribution c. a chi-square distribution

) is the t distribution only if the sample is drawn

Chapter 10 - Inference from Small Samples d. a population greater than 100 e. an F distribution ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 29. Suppose that a t-test is being conducted at the 0.05 level of significance to test

sample of size 20 is randomly selected. The rejection region is: a. t > 1.725 b. t < −1.729 c. t > −2.093 d. t < 2.086 e. t > 1.935 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 9:25 AM 30. The shape of the Student's t distribution depends on: a. the population variance b. the number of its degrees of freedom c. the population mean d. the number of its degrees of freedom and the population mean e. all of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 9:26 AM 31. Which of the following statements is false? a. The t distribution is symmetric about zero. b. The t distribution is more spread out than the standard normal distribution. c. As the degrees of freedom get smaller, the t distribution's dispersion gets smaller. d. The t distribution is mound-shaped.

Chapter 10 - Inference from Small Samples e. The t distribution is symmetric about zero and the t distribution is more spread out than the standard

normal distribution. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 32. Which of the following correctly describes Student's t distribution? a. It is a sampling distribution for a random variable, t, derived from a normally distributed population. b. It is single-peaked above the random variable's mean, median, and mode of 1. c. It is always skewed to the right. d. All of the above. e. None of these. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 7:55 AM 33. Which of the following correctly describes degrees of freedom? a. They are equal to the difference between the point estimate located at the interval center and either

the lower or upper limit of the interval between which the parameter is "free to move." b. They determine the shape of the t distribution, and refer to the number of independent squared deviations in that are available for estimating and, in this sense, can be "freely chosen." c. They equal sample size minus 2 in the case of a single sample. d. All of the above. e. None of these. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 7:58 AM 34. The t distribution table in your test shows: a. the area under a specified curve, defined by a given number of degrees of freedom , that lies to the

left of a specified value of t b. the area under a specified curve, defined by a given number of degrees of freedom, that lies to the right of a specified value of t

Chapter 10 - Inference from Small Samples c. specified values of t for the area under a specified curve, defined by a given number of degrees of

freedom d. the heights of a specified curve, defined by a given number of degrees of freedom, at various specified values of t e. specified values of t for different heights of a specified curve, defined by a given number of degrees of freedom ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 35. If you wish to estimate with 95% confidence the average number of miles that students living off-campus

commute to classes every day, a random sample of 20 students produced a mean equal to 5.2 miles and a standard deviation of 3.05 miles. Then, the appropriate critical value is: a. 1.96 b. 2.086 c. 2.093 d. 1.7291 e. 2.58 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 36. If you wish to estimate with 95% confidence the average number of miles that students living off-campus

commute to classes every day, a random sample of 20 students produced a mean equal to 5.2 miles and a standard deviation of 3.05 miles. Then, the upper limit for a 95% confidence interval estimate for the true population mean is approximately: a. 3.22 b. 6.63 c. 5.20 d. 2.15 e. 1.96 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM

Chapter 10 - Inference from Small Samples 37. If you wish to estimate with 95% confidence the average number of miles that students living off-campus

commute to classes every day, a random sample of 20 students produced a mean equal to 5.2 miles and a standard deviation of 3.05 miles. Then the point estimate for the true population mean is: a. 3.22 b. 6.63 c. 5.20 d. 2.15 e. 1.96 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 38. Which of the following statements is true with respect to the t distribution? a. The t distribution is more spread out than the standard normal distribution. b. The t distribution is symmetrical. c. The shape of the t distribution depends on the number of degrees of freedom. d. All of the above. e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 8:17 AM 39. Which of the following statements is true when small samples are used to estimate the true population mean

where the population standard deviation is unknown? a. The standard normal distribution must be used to obtain the critical value. b. The t distribution must be used to obtain the critical value. c. The margin of error for the confidence interval estimate tend to be very small. d. All of the above. e. None of these. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 9:27 AM

Chapter 10 - Inference from Small Samples 40. A random sample is selected from a normally distributed population. The following sample statistics are

obtained: n = 20, = 30, and s = 10. Based on this information, and using a 95% confidence level, which of the following statements is true? a. The critical value is 1.7921. b. The standard deviation of the sampling distribution of is .50. c. The margin of error is approximately 4.68. d. The critical value is 1.96. e. The margin of error is approximately 3.24. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 41. Under which of the following circumstances is it impossible to construct a confidence interval for the

population mean? a. A nonnormal population with a large sample and an unknown population variance. b. A normal population with a large sample and a known population variance. c. A nonnormal population with a small sample and an unknown population variance. d. A normal population with a small sample and an unknown population variance. e. A normal population with a large sample and an unknown population variance. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 9:34 AM 42. Suppose that a one-tailed t-test is being applied to find out if the population mean is less than 100. The level

of significance is 0.05 and 25 observations were sampled from a normally distributed population. The rejection region is: a. t > 1.708 b. t < −1.711 c. t > 1.318 d. t < −1.316 e. t < −1.542 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM

Chapter 10 - Inference from Small Samples DATE MODIFIED: 4/17/2019 9:36 AM 43. A random sample of size n has been selected from a normally distributed population whose standard

deviation is . In hypothesis testing for the population mean, the t-test should be used instead of the z-test if: a. n > 30 and is unknown b. n < 30 and is unknown c. n < 30 and is known d. n < 30 and is known e. n > 30 and is unknown and n < 30 and is known ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 44. In testing the hypotheses

vs.

the sample mean is found to be 120. The null hypothesis: a. should be rejected b. should not be rejected c. should be rejected only if n > 30 d. should be rejected only if n > 10 e. more information is needed to make the conclusion ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 9:39 AM 45. Researchers determined that 60 Kleenex tissues is the average number of tissues used during a cold.

Suppose a random sample of 100 Kleenex users yielded the following data on the number of tissues used during a cold: = 52 and s = 22. Suppose the test statistic does fall in the rejection region at = 0.05. Which of the following conclusions is correct? a. At = 0.05, we do not reject b. At

= 0.05, we reject

c. At

= 0.05, we accept

d. At

= 0.10, we do not reject

Chapter 10 - Inference from Small Samples e. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 46. A robust estimator is one that: a. is unbiased and symmetrical about zero b. is consistent and is also mound-shaped c. is efficient and less spread out d. is not sensitive to moderate departure from the assumption of normality in the population e. is equal to the mean ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 47. Which of the following statements is true? a. The t distribution starts at zero. b. The t distribution is more spread out than the standard normal distribution. c. As the degrees of freedom get smaller, the t distribution's dispersion gets smaller. d. The t distribution is nonsymmetric. e. The t distribution is more spread out than the standard normal distribution and as the degrees of

freedom get smaller, the t distribution's dispersion gets smaller. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 9:08 AM 48. For a sample of size 20 taken from a normally distributed population with standard deviation equal to 5, a

90% confidence interval for the population mean would require the use of: a. t = 1.328 b. t = 1.729 c. z = 1.96 d. z = 1.645 e. z = 2.58

Chapter 10 - Inference from Small Samples ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 9:16 AM 49. Which of the following is true about the t distribution? a. It approaches the normal distribution as its degrees of freedom increase. b. It assumes the population is normally distributed. c. It is more spread out than the standard normal distribution. d. All of the above. e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 9:17 AM 50. A major department store chain is interested in estimating the average amount its credit card customers spent

on their first visit to the chain's new store in the mall. Fifteen credit card accounts were randomly sampled and analyzed with the following results: = $50.50 and = 400. Assuming the distribution of the amount spent on their first visit is approximately normal, what is the shape of the sampling distribution of the sample mean that will be used to create the desired confidence interval for ? a. Approximately normal with a mean of $50.50. b. A standard normal distribution. c. A t distribution with 15 degrees of freedom. d. A t distribution with 14 degrees of freedom. e. Approximately normal with a mean of $80.20. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 51. Researchers determined that 60 Kleenex tissues is the average number of tissues used during a cold.

Suppose a random sample of 100 Kleenex users yielded the following data on the number of tissues used during a cold: = 52 and s = 22. Suppose the alternative we wanted to test was . The correct rejection region for = 0.05 is a. reject

if t > 1.6604

Chapter 10 - Inference from Small Samples b. reject

if t < −1.6604

reject

if t > 1.9842 or Z < −1.9842

reject

if t < −1.9842

reject

if t > −1.9842

d. e.

ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 9:41 AM 52. Which of the following is not true about the Student's t distribution? a. It has more area in the tails and less in the center than does the normal distribution. b. It is used to construct confidence intervals for the population mean when the population standard

deviation is known. c. It is bell shaped and symmetrical. d. As the number of degrees of freedom increases, the t distribution approaches the normal distribution. e. The shape of the t distribution depends on the sample size. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 10:23 AM 53. A random sample of size 15 taken from a normally distributed population revealed a sample mean of 75 and

a sample variance of 25. The upper limit of a 95% confidence interval for the population mean would equal: a. 77.769 b. 72.231 c. 72.727 d. 77.273 e. 77.145 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 54. A major department store chain is interested in estimating the average amount its credit card customers spent

Chapter 10 - Inference from Small Samples

on their first visit to the chain's new store in the mall. Fifteen credit card accounts were randomly sampled and analyzed with the following results: = $50.50 and = 400. Assume that the sample is selected from a normally distributed population. A 95% confidence interval for the average amount the credit card customers spent on their first visit to the chain's new store in the mall is: a. $50.50 $9.09 b. $50.50 $10.12 c. $50.50 $11.00 d. $50.50 $11.08 e. $50.50 $11.79 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 10:35 AM 55. Private colleges and universities rely on money contributed by individuals and corporations for their

operating expenses. Much of this money is put into a fund called an endowment, and the college spends only the interest earned by the fund. A recent survey of 8 private colleges in the United States revealed the following endowments (in millions of dollars): 60.2, 47.0, 235.1, 490.0, 122.6, 177.5, 95.4, and 220.0. Summary statistics yield =180.975 and s = 143.042. Assume that the sample is selected from a normally distributed population. A 95% confidence interval for the mean endowment of all the private colleges in the United States is: a. $180.975 $94.066 b. $180.975 $99.123 c. $180.975

$116.621 d. $180.975 $116.983 e. $180.975 $119.605 ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 10:40 AM 56. Researchers determine that 60 Kleenex tissues is the average number of tissues used during a cold. Suppose

a random sample of 100 Kleenex users yielded the following statistics on the number of tissues used during a cold: = 52 and s = 22. Using the sample information provided, the value of the test statistic is: a. t = (52 − 60)/22 b. t = (52 − 60)/(22/100) c. t = (52 − 60)/(22/ d. t = (52 − 60)/(22/10)

)

Chapter 10 - Inference from Small Samples e. t = (52 − 60)/(22/

)

ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 9:43 AM 57. If you were constructing a 99% confidence interval of the population mean based on a sample of n = 25

from a normally distributed population where the standard deviation of the sample s = 0.05, the critical value of t will be: a. 2.7969 b. 2.7874 c. 2.4922 d. 2.4851 e. 2.3562 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 10:47 AM 58. Given a random variable that has a t distribution with the specified degrees of freedom, what percentage of

the time will its value fall in the indicated region? 15 degrees of freedom, between −2.131 and 2.131 (Enter as a decimal percent or use the % sign.) 19 degrees of freedom, between −2.539 and 2.539 (Enter as a decimal percent or use the % sign.) 23 degrees of freedom, between −1.319 and 1.319 (Enter as a decimal percent or use the % sign.) 10 degrees of freedom, between −3.169 and 3.169

ANSWER:

(Enter as a decimal percent or use the % sign.) 95%; 98%; 80%; 99%

POINTS: QUESTION TYPE: HAS VARIABLES:

1 Subjective Short Answer False

Chapter 10 - Inference from Small Samples STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 9:43 AM 59. What is the appropriate t critical value for each of the following confidence levels and sample sizes when

testing the two-sided alternative hypothesis? Give your answers to three decimal places. 80% confidence, n = 17

90% confidence, n = 7

99% confidence, n = 4

95% confidence, n = 14

ANSWER:

1.337; 1.943; 5.841; 2.16

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 11:01 AM 60. Let denote the true average number of minutes of a television commercial. Suppose the hypotheses

are tested. Assuming the commercial time is normally distributed, give the appropriate upper critical value for each of the following sample sizes and significance levels. Give your answers to three decimal places. n = 6, = 0.01

n = 12, = 0.05

n = 20, = 0.05

Chapter 10 - Inference from Small Samples

n = 23, = 0.1

You may use the Data Analysis software to find the answers. ANSWER: 4.032; 2.201; 2.093; 1.717 POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 11:10 AM 61. The average gas mileage of a 4-wheel drive truck is 18.2 miles per gallon. The average gas mileage for 7

randomly selected trucks are listed below.

a. Assume the gas mileage distribution is normal. It is of interest to know if the sample data suggest the average gas mileage is different from 18.2 miles per gallon. What are the appropriate hypotheses?

b. Compute the test statistic for the hypotheses in (a). Test Statistic =

Give your answer to four decimal places.

c. Compute the approximate p-value associated with the test statistic in (b). P-Value =

Give your answer to two decimal places.

d. Does the sample data support the null hypothesis at the = 0.05 level?

ANSWER:

; 0.2727; 0.79; Yes

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 11:20 AM 62. A drapery store manager was interested in determining whether a new employee can install vertical blinds

faster than an employee who has been with the company for two years.

Chapter 10 - Inference from Small Samples

The manager takes independent samples of 10 vertical blind installations of each of the two employees and computes the following information.

Assume that the samples were randomly selected from normally distributed populations with equal variances. Give your answers to three decimal places. a. State the appropriate null and alternative hypotheses to test whether the new employee installs vertical blinds faster, on the average, than the veteran employee.

b. Calculate the pooled estimate of the common variance.

c. Calculate the value of the test statistic.

d. Find the appropriate critical value for the hypotheses assuming = 0.05.

e. What is the appropriate conclusion? The new employee ANSWER:

install vertical blinds faster than the veteran employee. ; .686; −7.018; −1.734; does

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 9:51 AM 63. A logger knows the average time for his cutting machine to cut 20 trees is 9.8 minutes. A new machine on

the market claims to cut the trees in less than 9.8 minutes. A random sample of 25 test runs on the new machine yielded a mean of 8.5 minutes with a standard deviation of 1.5. Does the sample data suggest the new machine cuts faster than the logger's machine? Test at the = 0.05 level. Assume the cutting time is normally distributed and interpret your results.

Chapter 10 - Inference from Small Samples

Test Statistic =

Give your answer to two decimal places.

The new machine

cut faster than the logger's machine. −4.33; Reject the null hypothesis; does

ANSWER:

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 9:53 AM 64. The length of duration, in minutes, of earthquakes in California has been recorded for future analysis and

information. The length of duration of a random sample of 6 earthquakes are listed below: 1.1, 0.9, 1.5, 0.7, 1.4, 1.3 Assuming the distribution of the length of duration of the earthquakes is approximately normal, find a 98% confidence interval for the true average duration of earthquakes in California. a. What is the 98% Confidence Interval (CI)? CI =

Enter (n1, n2). Give your answer to three decimal places.

An earthquake expert claims that the average duration of earthquakes in California is 0.5 minutes. Based on the interval in part (a), can this claim be rejected?

b. Justify your answer.

ANSWER:

(.0.727, 1.573); Reject the claim; Since 0.5 is outside the limits of the 98% confidence interval. one can reject the expert's claim that the true average duration of earthquakes in California is 0.5 minutes

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 11:57 AM 65. The average life of a certain type and brand of battery is 75 weeks. The average life of each of 9 randomly

selected batteries is listed below. 74.5, 75.0, 72.3, 76.0, 75.2, 75.1, 75.3, 74.9, 74.8

Chapter 10 - Inference from Small Samples

a. Assume the battery life distribution is normal. It is of interest to know if the sample data suggest the average life is smaller than 75 weeks. b. Compute the test statistic for the hypotheses in part (a). Test statistic =

Give your answer to two decimal places.

c. Compute the approximate p-value associated with the test statistic in (b). P-value =

Give your answer to three decimal places.

Conclusion: The sample data ANSWER:

support the alternative hypothesis at the = 0.05 level. −0.62; 0.276; Do not reject H0; does not

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 9:55 AM 66. A garment manufacturing company recorded the amount of time that it took to make a pair of jeans on 8

different occasions. The times in minutes are as follows: 12.5, 13.0, 11.9, 10.2, 13.1, 13.6, 13.8, and 14.0. Assume these measurements were taken from a population with a normal distribution. It is of interest to know if the sample data suggest that the average time it takes this company to make a pair of jeans is less than 13.5 minutes. Does the sample data support the alternative hypothesis at the = 0.05 level? Give your answers to three decimal places. Test statistic = Critical Value(s) = Conclusion: Interpretation: The average time it takes this company to make a pair of jeans minutes.

less than 13.5

Construct a 95% confidence interval for the mean amount of time it takes this company to make a pair of jeans.

ANSWER:

−1.675; −1.895; Do not reject H0; is NOT; (11.928, 13.597)

Chapter 10 - Inference from Small Samples POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:14 AM 67. The average low temperature for Champlin, MN in November is 12 degrees F. The average low temperature

for each of 8 randomly selected years is listed below. 11.0, 12.4, 11.8, 10.9, 11.4, 12.2, 10.8, 12.2 a. Assume the November low temperature distribution is normal. It is of interest to know if the sample data suggest the average low temperature is lower than 12 degrees F. b. Compute the test statistic for the hypotheses in (a). Test Statistic =

Give your answer to two decimal places.

c. Compute the approximate p-value associated with the test statistic in (b). What is the p-value? Give your answer to three decimal places. Conclusion: The sample data ANSWER:

support the null hypothesis at the

level?

−1.80; 0.057; Do not reject H0; does.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 9:57 AM 68. Ten measurements of the tar content of a certain brand of cigarette are listed below in milligrams per

cigarette. Assume these measurements were taken from a population with a normal distribution. 13.5, 14.0, 13.9, 14.2, 15.1, 14.6, 13.8, 14.0, 14.1, 14.7 Construct a 90% confidence interval for the mean tar content of any cigarette of this brand. a. What is the 90% confidence interval (CI)? CI =

Enter (n1, n2). Give your answer to three decimal places.

Interpret the interval in part (a).

Chapter 10 - Inference from Small Samples

ANSWER:

(13.913, 14.467); One can estimate with 90% confidence that the mean tar content of any cigarette of this brand is roughly between 13.9 and 14.5 milligrams

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 8:23 PM 69. One study revealed that the average child under the age of 10 watches television 4.5 hours per day.

a. A group of families from a certain community would like to believe that their children watch television less than the national average. A random sample of 14 children from the community yielded a mean of 4.1 hours per day with a standard deviation of 1.2. Test the appropriate hypotheses at the = 0.01 level. Assume the viewing time is normally distributed and interpret your results. b. Compute the test statistic for the hypotheses in (a). Test Statistic =

Give your answer to three decimal places.

Conclusion: The sample data ANSWER:

support the null hypothesis at the

level?

−1.247; Do not reject H0; does.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:16 AM 70. The manufacturer of a particular battery pack for laptop computers claims its battery pack can function for 8

hours, on the average, before having to be recharged. A random sample of 16 battery packs was selected and tested. The mean functioning time before having to be recharged was 7.2 hours with a standard deviation of 1.9 hours. Assuming the distribution of functioning times is approximately normal, find a 95% confidence interval for the true average functioning time before needing to be recharged. Interpret the interval in part (a). Based on the interval in part (a), can the manufacturer's claim be rejected? Justify your answer. a. What is the 95% confidence interval (CI)? CI =

Enter (n1, n2). Give your answer to three decimal places.

Chapter 10 - Inference from Small Samples

Interpret the interval:

The claim

be rejected.

Justify your answer:

ANSWER:

(6.188, 8.212); One can estimate with 95% confidence that the true average time the battery pack will function before needing to be recharged is between 6.188 and 8.212 hours.; can not; Since 8 is within the limits of the confidence interval, the claim cannot be rejected.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 8:33 PM 71. The public relations officer for a particular city claims the average monthly cost for childcare outside the

home for a single child is $600. A potential resident is interested in whether the claim is correct. She obtains a random sample of 14 records and computes the average monthly cost of this type of childcare to be $589 with a standard deviation of $40. Perform the appropriate test of hypothesis for the potential resident using . Approximate the p-value for the test in (a). Give your answers to three decimal places.

a. Test Statistic = b. Compute the approximate p-value associated with the test statistic in (a). c. What is the p-value? _ Conclusion: The sample data ANSWER:

support the null hypothesis at the −1.029; .322; Do not reject H0; does

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:17 AM

level?

Chapter 10 - Inference from Small Samples 72. It is of interest to a Harley Davidson dealer to know the average gas mileage of a 1992 XLT. A random

sample of 17 was taken from a normally distributed population and produced a mean of 52 miles per gallon and a standard deviation of 4.1 miles per gallon. Construct a 95 percent confidence interval for the mean gas mileage of any 1992 Harley Davidson XLT. Interpret the interval in part (a). The dealer claims that the average gas mileage of Harley Davidson 1992 XLT is 58 miles per gallon Based on the interval in part (a), can this claim be rejected? Justify your answer. a. What is the 95% confidence interval (CI)? CI =

Enter (n1, n2). Give your answer to three decimal places.

Interpret the interval:

The claim

be rejected.

Justify your answer:

ANSWER:

(49.892, 54.108); One can estimate with 95% confidence that the true average gas mileage of Harley Davidson 1992 XLT is roughly between 49.9 and 54.1 miles per gallon.; can; Since 58 is outside the limits of the 95% confidence interval, one can reject the dealer’s claim.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/16/2019 8:41 PM 73. An automatic coffee vending machine dispenses a different amount of coffee in ounces for each cup.

Assume the nine measurements below were taken from a population with a normal distribution. 6.5, 6.0, 6.9, 6.2, 6.1, 6.6, 6.8, 6.0, 6.1 Construct an 80% confidence interval for the mean amount of ounces that is dispensed for all cups of coffee from this machine. Interpret the interval in part (a). a. What is the 80% confidence interval (CI)? CI =

Enter (n1, n2). Give your answer to three decimal places.

Interpret the interval:

ANSWER:

(6.192, 6.519); One can estimate with 80% confidence that the mean amount of ounces that is dispensed for all cups of coffee from this machine is roughly

Chapter 10 - Inference from Small Samples

between 6.2 and 6.5. POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 6:03 AM 74. The test scores on a 100-point test were recorded for 20 students:

Can you reasonably assume that these test scores have been selected from a normal population? Use a stem and leaf plot to justify your answer. Calculate the mean and standard deviation of the scores. If these students can be considered a random sample from the population of all students, find a 95% confidence interval for the average test score in the population. These test scores Mean =

been selected from a normal population. _ Give your answer to two decimal places.

Standard Deviation =

Give your answer to four decimal places.

What is 95% confidence interval? (CI) CI = ANSWER:

Enter (n1, n2). Give your answer to four decimal places. have; 78.15; 9.6588; (73.6296, 82.6704)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 7:33 AM 75. The following n = 10 observations are a sample from a normal population: 10.4 10.1 9.5 10.5 10.6 9.3 9.9

Chapter 10 - Inference from Small Samples

10.7 9.5 10.0 Find the mean and standard deviation of these data. Find a 99% confidence interval for the population mean . Test conclusion in part (c). Mean =

. Use

_ Give your answer to two decimal places.

Standard Deviation = Test Statistic =

= 0.01 Do the results of part (b) support your

Give your answer to four decimal places. Give your answer to two decimal places.

Conclusion: What is 99% confidence interval? (CI) CI = ANSWER:

Enter (n1, n2). Give your answer to four decimal places. 10.05; .4994; −2.85; Reject H0; (9.5367, 10.5633)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:19 AM 76. Here are the red blood cell counts (in 106 cells per microliter) of a healthy person measured on each of 15

days:

Find a 95% confidence interval estimate of the true mean red blood cell count for this person during the period of testing. What is 95% confidence interval? (CI) CI = ANSWER:

Enter (n1, n2). Give your answer to four decimal places. (5.3517, 5.5283)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 7:16 AM 77. An experiment to determine the efficacy of using 95% ethanol or 20% bleach as a disinfectant in removing

bacterial and fungal contamination when culturing plant tissues was repeated 15 times for each disinfectant. The plant tissue being cultured was sweet potato: Five cuttings per plant were placed on a petri dish for each

Chapter 10 - Inference from Small Samples

disinfectant and stored at 25 C for 4 weeks. The observation reported was the number of uncontaminated cuttings after the 4-week storage.

a. Is it reasonable to assume that the underlying variances are equal?

b. Are you willing to conclude that there is a significant difference in the mean numbers of uncontaminated eggplants for the two disinfectants at the 1% significance level? t= There disinfectants. ANSWER:

Give your answer to two decimal places. evidence of a difference in the mean number of uncontaminated eggplants for the two No; −2.42; is

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:20 AM 78. The following data were drawn from a normal population: 15, 4, 24, 8, 16, 13, 9, 15, 7, and 22. Estimate the

population mean with 90% confidence. What is 90% confidence interval? (CI) CI = ANSWER:

Enter (n1, n2). Give your answer to three decimal places. (9.553, 17.047)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 7:17 AM 79. A random sample of 7 observations was drawn from a normal population. The following summations were

computed:

Chapter 10 - Inference from Small Samples

Test the hypotheses H0: = 8 vs. H1: > 8 at the 1% significance level. Test statistic =

Give your answer to two decimal places.

Critical Value(s) =

Give your answer to three decimal places.

Conclusion: Interpretation: ANSWER:

3.40; 3.143; Reject H0; The population mean is larger than 8 at the 1% significance level.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 7:56 AM 80. A simple random sample of 100 grocery receipts was drawn from a normal population. The mean and

standard deviation of the sample were $120 and $25, respectively. Test the hypotheses H0: = 125 vs. H1: 125 at the 10% significance level. Give yor answers to two decimal places.

Test statistic = Critical Value(s) = Conclusion: Interpretation: Estimate the population mean with 90% confidence.

ANSWER:

−2.0; −1.66, 1.66; Reject H0; The population mean is not 125 at the 10% significance level; (115.85, 124.15)

POINTS: QUESTION TYPE: HAS VARIABLES:

1 Subjective Short Answer False

Chapter 10 - Inference from Small Samples STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:21 AM 81. A random sample of 15 hourly wages for waitresses (including tips) was drawn from a normal population.

The sample mean and sample standard deviation were computed as = $14.9 and s = $6.75. Can we infer at the 5% significance level that the population mean is greater than 12? Give your answers to three decimal places.

Test statistic = Critical Value(s) = Conclusion: Interpretation: Can we infer at the 5% significance level that the population mean is greater than 12, assuming that you know the population standard deviation is equal to 6.75? Test statistic = Critical Value(s) = Conclusion: Interpretation: ANSWER:

1.664; 1.761; Do not reject H0; No, we CANNOT make this inference; 1.664; 1.645; Reject H0; Yes, we can make this inference

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 8:18 AM 82. A psychologist is trying to determine how many hours the average person sleeps each night. He takes a

random sample of 25 individuals and asks each person how many hours he or she slept the previous night. The sum of the observations and the sum of the squared observations are:

Estimate with 99% confidence the mean number of hours of sleep.

Chapter 10 - Inference from Small Samples

ANSWER:

Enter (n1, n2). Give your answer to three decimal places. (6.897,8.503)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 8:23 AM 83. During a water shortage, a water company randomly sampled residential water meters in order to monitor

daily water consumption. On a particular day, a sample of 100 meters showed a sample mean of 250 gallons and a sample standard deviation of 50 gallons. Provide a 90% confidence interval estimate of the mean water consumption for the population.

ANSWER:

Round your answer to one decimal place. (241.7, 258.3)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 8:27 AM 84. In testing the difference between two population means using two independent samples, the sampling

distribution of the difference in the sample means, 30.

, is normal if the sample sizes are both greater than

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/3/2019 8:00 AM 85. Two samples of sizes 15 and 20 are randomly and independently selected from two normally distributed

populations, where the unknown population variances are assumed to be equal. The number of degrees of freedom associated with the two-sample t-test is equal to 35. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False

Chapter 10 - Inference from Small Samples DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 86. The pooled-variances t-test requires that the two population variances need not be the same. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 87. In testing the difference between two population means using two independent samples, we use the pooled

variance in estimating the standard error of the sampling distribution of the difference in the sample means, , if the populations are normal with equal variances. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/3/2019 8:02 AM 88. A political analyst in Iowa surveys a random sample of registered Democrats and compares the results with

those obtained from a random sample of registered Republicans. This would be an example of two independent samples. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 89. In testing the difference between two population means using two independent samples, the population

standard deviations are assumed to be known, and the calculated test statistic equals 2.75. If the test is twotailed and 5% level of significance has been specified, the conclusion should not reject the null hypothesis. a. True b. False ANSWER: POINTS:

False 1

Chapter 10 - Inference from Small Samples QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/2/2019 8:29 AM 90. When the necessary conditions are met, a two-tailed test is being conducted to test the difference between

two population means, but your statistical software provides only a one-tailed area of 0.045 as part of its output. The p-value for this test will be 0.09. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/2/2019 8:38 AM 91. Two samples of sizes 25 and 20 are independently drawn from two normal populations, where the unknown

population variances are assumed to be equal. The number of degrees of freedom of the equal-variances t-test statistic is 44. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 92. The sampling distribution of

is normal if the sampled populations are normal, and approximately normal if the populations are nonnormal and the sample sizes and are large. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/3/2019 8:05 AM 93. The mean value of a. True b. False ANSWER: True

is equal to

Chapter 10 - Inference from Small Samples POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM

94. The variance of

is equal to

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 95. The equal-variances test statistic of

is Student t distributed with

degrees of freedom,

provided that the two populations are normal. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:26 AM 96. When the population variances are unequal, we estimate each population variance with its sample variance.

Hence, the unequal-variances test statistic of of freedom.

follows the Student's t distribution with

− 2 degrees

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:24 AM 97. The unequal-variances test statistic and confidence interval estimator of

population variances are unequal. a. True

can be used only if

Chapter 10 - Inference from Small Samples b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/3/2019 8:09 AM 98. Both the equal-variances and unequal variances test statistic and confidence interval estimator of

require that the two populations be normally distributed. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 99. The sample size in each independent sample must be the same if we are to test for differences between the

means of 2 independent populations. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 100. When we test for differences between the means of two independent populations, we can only use a two-

tailed test. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 101. Which of the following is not a required assumption for constructing a confidence interval estimate of the

difference between two population means when the samples are small? a. The populations are normally distributed.

Chapter 10 - Inference from Small Samples b. The population variances are equal. c. The population variances are equal to 1. d. The samples are selected at random from the populations. e. None of these. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/2/2019 10:36 AM 102. In testing the difference between two population means, which of the following assumptions is not true for

the two-sample procedure that uses a pooled estimate of the common variance ? a. The two samples must be independent of each other. b. The two samples must be small and selected at random from the populations. c. The populations from which the samples are drawn must be t-distributed. d. The population variances should be equal or nearly equal. e. None of these. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 103. Under what conditions can the t-distribution be correctly employed to test the difference between two

population means? a. The samples must be small and selected at random from the population. b. The samples must be independent of each other. c. The population variances should be equal or nearly equal, and the populations must be normally

distributed. d. All of the above. e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/2/2019 10:38 AM 104. Two independent samples are selected at random from two normal populations, where the unknown

population variances are assumed to be equal. The sample statistics are as follows:

Chapter 10 - Inference from Small Samples

and statistic?

Assume that a two-tailed hypothesis test is conducted at

, what is the value of the test

a. z = 1.645 b. t = 0.891 c. z = 1.960 d. t = 0.928 e. t = 0.945 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/2/2019 11:02 AM 105. Two independent samples are selected at random from two normal populations, where the unknown

population variances are assumed to be equal. The sample statistics are as follows: and

Assume that a two-tailed hypothesis test is conducted at

, what is the upper critical value?

a. t = 2.0484 b. z = 1.96 c. t = 1.7011 d. z = 1.65 e. t = 1.562 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:37 AM 106. Two samples of sizes 25 and 35 are independently drawn from two normal populations, where the

unknown population variances are assumed to be equal. The number of degrees of freedom of the equalvariances t-test statistic is: a. 60 b. 59 c. 58 d. 35 e. 34 ANSWER: POINTS:

c 1

Chapter 10 - Inference from Small Samples QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 107. In constructing 95% confidence interval estimate for the difference between the means of two normally

distributed populations, where the unknown population variances are assumed not to be equal, summary statistics computed from two independent samples are as follows:

, and

. The upper confidence limit is: a. 19.123 b. 28.28 c. 24.911 d. 5.788 e. 22.934 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 108. In testing the difference between the means of two normally distributed populations, the number of degrees

of freedom associated with the unequal-variances t-test statistic usually results in a non-integer number. It is recommended that you: a. take the integer part of the result b. decrease the sample sizes until the number of degrees of freedom becomes an integer c. increase the sample sizes until the number of degrees of freedom becomes an integer d. assume that the population variances are equal, and then use df = e. assume that the population variances are equal, and then use df = ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/2/2019 11:43 AM 109. The quantity

is called the pooled variance estimate of the common variance of two unknown but equal population variances. It is the weighted average of the two sample variances, where the weights represent the: a. sample variances b. sample standard deviations c. sample sizes

Chapter 10 - Inference from Small Samples d. degrees of freedom for each sample e. sample means ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/2/2019 11:44 AM 110. Two independent samples of sizes 20 and 30 are randomly selected from two normally distributed

populations. Assume that the population variances are unknown but equal. To test the difference between the population means,

, the sampling distribution of the difference in the sample means,

, is:

a. normally distributed b. t-distributed with 50 degrees of freedom c. t-distributed with 48 degrees of freedom d. F-distributed with 19 and 29 degrees of freedom e. z-distributed with 30 degrees of freedom ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/2/2019 11:55 AM 111. Two independent samples of sizes 40 and 50 are randomly selected from two populations to test the

difference between the population means, means,

. The sampling distribution of the difference in the sample

, is:

a. normally distributed b. approximately normal c. Student t-distributed with 88 degrees of freedom d. Student t-distributed with 25 degrees of freedom e. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/2/2019 11:59 AM 112. Two independent samples of sizes 25 and 35 are randomly selected from two normal populations with

equal variances. In order to test the difference between the population means, the test statistic is:

Chapter 10 - Inference from Small Samples a. a standard normal random variable b. approximately standard normal random variable c. Student t-distributed with 58 degrees of freedom d. Student t-distributed with 33 degrees of freedom e. Student t-distributed with 18 degrees of freedom ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 113. In testing the difference between two population means using two independent samples, we use the pooled

variance in estimating the standard error of the sampling distribution of the difference in the sample means, , if: a. the sample sizes are both large b. the populations are normal with equal variances c. the populations are normal with unequal variances d. the populations are non-normal with unequal variances e. all of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/2/2019 12:08 PM 114. In testing the difference between two population means using two independent samples, the sampling

distribution of the difference in the sample means,

, is normal if:

a. the sample sizes are both greater than 30 b. the populations are normal c. the populations are non-normal and the sample sizes are small d. the populations are non-normal and the sample sizes are large e. all of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/2/2019 12:13 PM

Chapter 10 - Inference from Small Samples 115. In testing whether the means of two normal populations are equal, summary statistics computed for two

independent samples are as follows: , , , , , and . Assume that the population variances are equal. Then, the standard error of the sampling distribution of the difference in the sample means,

, is equal to:

a. 0.1017 b. 1.2713 c. 0.3189 d. 1.1275 e. 0.4812 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/2/2019 12:14 PM 116. In constructing a confidence interval estimate for the difference between the means of two normally

distributed populations, using two independent samples, we: a. pool the sample variances when the unknown population variances are equal b. pool the sample variances when the population variances are known and equal c. pool the sample variances when the population means are equal d. pool the sample variances when the unknown population variances are unequal e. never pool the sample variances ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 117. The t-test for the difference between the means of two independent populations assumes that the respective: a. sample sizes are equal b. sample variances are equal c. populations are approximately normal d. all of the above e. none of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM

Chapter 10 - Inference from Small Samples DATE MODIFIED: 4/2/2019 12:16 PM 118. If we are testing for the difference between the means of two independent populations with equal variances,

samples of a. 29 b. 28 c. 14 d. 13 e. 11

and

are taken, then the number of degrees of freedom is equal to:

ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 119. In testing for the differences between the means of two independent normal populations where the

variances in each population are unknown but assumed equal, the degrees of freedom are: a. b. c. d. e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/2/2019 12:18 PM 120. In testing for differences between the means of two independent populations the null hypothesis is: a. b. c. d. e. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice

Chapter 10 - Inference from Small Samples HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 121. Given the information:

, the number of degrees of freedom that should be used in

the pooled-variance t-test is: a. 40 b. 38 c. 15 d. 25 e. 32 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/2/2019 12:23 PM 122. Assume that the population distributions of ages (in years) of students at two different universities in

Michigan are normal with equal variances. Two random samples, drawn independently from the populations, showed the following statistics.

Construct and interpret a 99% confidence interval for the true difference in average ages of students at both universities using the pooled-variance t-test. What is the 99% confidence interval? (CI) CI =

Enter (n1, n2). Give the limits of CI rounded to two decimal places.

The sample evidence supports that the two universities' students ages. ANSWER: (−2.36, 4.36); do not

have significantly different

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:39 AM 123. A computer laboratory manager was in charge of purchasing new battery packs for her lab of laptop

Chapter 10 - Inference from Small Samples

packs would function before needing to be recharged. She took two independent samples and computed the following summary information:

Is it reasonable to assume equality of variances in this problem? Justify your answer.

Give the t-value to four decimal places.

Conclusion: One conclude that there is a significant difference in the average functioning time before recharging between the two models of battery packs. ANSWER:

Yes, since 2.25/1.69 < 3;−0.7557; Do not reject H0; cannot

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:40 AM 124. Set up the rejection regions for the following testing conditions. Assume the assumptions of normality and

equal variances are satisfied. Give your answers to three decimal places.

ANSWER:

t > 2.086 or t < −2.086; t > 2.764; t < −1.701

POINTS: QUESTION TYPE:

1 Subjective Short Answer

Chapter 10 - Inference from Small Samples HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:40 AM 125. A customer service representative was interested in comparing the average time (in minutes) customers are

placed on hold when calling Southern California Edison and Southern California Gas companies. The representative obtained two independent random samples and calculated the following summary information:

Assume the distributions of time a customer is on hold are approximately normal. Is it reasonable to assume equality of variances in this problem?

Test whether there is a significant difference in the average time a customer is on hold between the two companies. Calculate the value of the test statistic. Set up the appropriate rejection region for the test in part (a) assuming = 0.10. What is the appropriate conclusion? Test Statistic =

Give the t-value to two decimal places.

Reject Region: Reject H0 if |t| >

Give the critical value to three decimal places.

Conclusion: One conclude that there is a significant difference in mean time a customer is on hold between the two companies. ANSWER:

Yes, since 0.49/0.25 < 3; 1.53; 1.729; Do not reject H0; cannot

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/3/2019 10:24 AM 126. The mean driving times (in minutes) on 5 different days for Abby and Steve to drive to their classes at

Michigan State University are listed below.

Chapter 10 - Inference from Small Samples

Is there sufficient evidence to conclude that the mean driving times for both students differ? Assume the population distributions are normal and have equal variances. Use a 0.01 significance level. Test Statistic =

Give the t-value to two decimal places.

Reject Region: Reject H0 if |t| >

Give the critical value to three decimal places.

Conclusion: There ANSWER:

enough evidence to conclude that the driving times for Abby and Steve differ. −2.18; 3.355; Do not reject H0; is not

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:41 AM 127. Assume that the population distributions of times (in minutes) for two different skiers to race the same

course are normal with equal variances. Two random samples, drawn independently from the populations, showed the following statistics.

Construct and interpret a 95% confidence interval for the true difference in average time of skiers to race the same course. What is the 95% confidence interval? (CI) CI = The sample evidence ANSWER:

Enter (n1, n2). Give the limits to three decimal places. support that the two skiers, on average, have different race times. (−1.482, −0.218); does

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:41 AM 128. A child psychologist was interested in the difference in age (in years) between boys and girls when they

Chapter 10 - Inference from Small Samples

first learn to ride a two-wheeled bicycle. The psychologist developed a 99% confidence interval for the difference in average ages to be (−0.58, 0.73). What conclusion, if any, can be drawn from this interval? Since 0 is included in the interval, one conclude there is a difference in age, on the average, at which boys and girls first learn to ride a two-wheeled bicycle. ANSWER: cannot POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:42 AM 129. In an effort to raise ratings, a television network president decides to reduce the number of commercials. A

random sample of 8 one-hour programs was monitored from each of two major networks. The data below reflect the time in minutes of commercials for each of the 16 shows.

Suppose denotes the mean commercial time for network 1 and denotes the mean commercial time for network 2. Estimate using a 95% confidence interval. Assume both population distributions are normal and have equal variances. What is the 95% confidence interval? (CI) CI =

Enter (n1, n2). Give the limits to one decimal place.

Since this interval contains zero, we are commercial times. ANSWER: (−1.800, 1.200); unable

to say the two networks have significantly different

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:42 AM 130. The mean playing times (in hours) for 5 different co-ed volleyball games for two different teams are listed

below.

Chapter 10 - Inference from Small Samples

Is there sufficient evidence to conclude the mean playing time for the two teams differ? Assume the population distributions are normal and . Use a 0.05 significance level. Test Statistic =

Give the t-value to four decimal places.

Reject Region: Reject H0 if |t| >

Give the limit to four decimal places.

Conclusion: One times. ANSWER:

conclude that there is sufficient evidence to claim the two teams have different playing 0.5058; 2.306; Do not reject H0; cannot

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/2/2019 1:56 PM 131. Assume that the population distributions of times (in hours) of two different surgeries are normal with

equal variances. Two random samples, drawn independently from the populations, showed the following statistics.

Construct and interpret a 90% confidence interval for the true difference in the mean amount of time of the two surgeries. What is the 90% confidence interval? (CI) CI =

Enter (n1, n2). Give the limits to three decimal places.

Since this interval contains zero, the sample evidence average, do not take significantly different amounts of time. ANSWER: (−0.295, 0.095); does POINTS:

support that the two surgeries, on

Chapter 10 - Inference from Small Samples QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:42 AM 132. Assume that the population distributions of life expectancy (in years) of men and women are normal with

equal variances. Two random samples, drawn independently from the populations, showed the following statistics.

Construct and interpret a 99% confidence interval for the true difference in average life expectancy of men and women. What is the 99% confidence interval? (CI) CI =

Enter (n1, n2). Give the limits to three decimal places.

Since this interval does not contain zero, the sample evidence have, on average, different life expectancies. ANSWER: (−9.130, −4.870); does

support that men and women

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:43 AM 133. A social worker was interested in determining whether there is a significant difference in the average

monthly cost per child for childcare outside the home between state-supported facilities and privately owned facilities. Two independent random samples yielded the following information:

Is it reasonable to assume equality of variances in this problem? Justify your answer.

Perform the appropriate test of hypothesis to determine whether there is a significant difference in the average monthly cost per child for childcare between the two types of facilities. Use .

Chapter 10 - Inference from Small Samples

Test Statistic =

Give the t-value to three decimal places.

Reject Region: Reject H0 if |t| >

Give the limits to three decimal places.

Conclusion: One conclude that there is a significant difference in the average monthly cost per child for childcare outside the home between the two types of facilities. ANSWER:

Yes, since 822 /682 < 3; 0.891; 1.734; Do not reject H0; cannot

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/3/2019 10:23 AM 134. A faculty advisor was interested in determining whether there is a difference in the amount of time (in

hours) spent studying on weeknights (Monday through Thursday) between male and female students. The advisor selected a sample of 12 female students and a second independent sample of 10 male students and asked each student to indicate the average amount of time they spend studying on a weeknight. The following summary statistics are obtained.

The advisor assumed equal variances in the analysis. Is this a reasonable assumption?

Perform the appropriate test of hypothesis to determine whether there is a significant difference in the average time spent studying on weeknights between male and female students Test using = 0.05. Using the p-value approach and = 0.10, what conclusion can be drawn about the difference in average time spent studying on weeknights between male and female students? Develop a 95% confidence interval for the average amount of time spent studying on week nights by females. Test Statistic = Reject Region: Reject H0 if |t| > Conclusion:

Give the t-value to four decimals. Give the limit to three decimals.

Chapter 10 - Inference from Small Samples

One conclude that there is a significant difference in average time spent studying on weeknights between male and female students. P-value =

Give the P-value to two decimals.

Using the p-value approach, one conclude there is a significant difference in average time spent studying on weeknights between male and female students. What is the 95% confidence interval? (CI) CI = ANSWER:

Enter (n1, n2). Give the limits to three decimals. Yes, since 0.8372/0.7492 < 3; −0.3637; 2.086; Do not reject H0; cannot; 0.72; cannot; (−0.828, 0.582)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:44 AM 135. A customer was interested in comparing the top speed (in miles per hour) of two models of snowmobiles.

The customer selected two independent random samples of the snowmobiles and calculated the following summary information:

Assume the distribution of top speeds is approximately normal. Is it reasonable to assume equality of variances in this problem?

Calculate the value of the test statistic. Test Statistic =

Give the t-value to two decimals.

Test whether there is a significant difference in average top speed between the two models of snowmobiles using . Reject Region: Reject H0 if |t| >

Give the limit to three decimals.

Chapter 10 - Inference from Small Samples

Conclusion: ANSWER:

Yes, since 25/9 < 3; 2.95; 2.131; Yes, there is a significant difference in average top speed between the two models of snowmobiles.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/3/2019 10:53 AM 136. Two independent random samples of sizes

= 4 and

= 5 are selected from each of two normal

populations:

Calculate

, the pooled estimator of

Give your answer to three decimal places. Find a 90% confidence interval for ( CI = Test

), the difference between the two population means.

Enter (n1, n2). Give the limits to three decimal places. for

= 0.05.

Conclusion: We ANSWER:

have sufficient evidence to indicate . 12.457; (−6.086, 2.886); do not

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:46 AM 137. 35 randomly selected employees who completed two years of college were asked to take a basic

mathematics test. The mean and standard deviation of their scores were 75.1 and 12.8, respectively. In a random sample of 50 employees who only completed high school, the mean and standard deviation of the test scores were 72.1 and 14.6, respectively. Assume that the population distributions are normal with equal variances. Can we infer at the 10% significance level that a difference exists between the two groups? Test statistic =

Give the t-value to two decimal places.

Chapter 10 - Inference from Small Samples

Critical Value(s) =

Give your answer to three decimal places.

Conclusion: Interpretation: Estimate with 90% confidence the difference in mean scores between the two groups of employees. Give the limits to two decimal places. ANSWER:

0.98; 1.664; Do not reject H0; A difference DOES NOT exist between the two groups; (−2.09, 8.09)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:47 AM 138. A food processor wants to compare two preservatives for their effects on retarding spoilage. Suppose 16

cuts of fresh meat are treated with preservative A and 16 are treated with preservative B, and the number of hours until spoilage begins is recorded for each of the 32 cuts of meat. The results are summarized in the table below:

Assume that the population distributions are normal with equal variances. Test to determine if the average number of hours until spoilage begins differs for the preservatives A and B. Determine the rejection region at = 0.05 and write the proper conclusion. Test statistic = Critical Value(s) =

Give the t-value to two decimal places. Give your answer to three decimal places.

Conclusion: Interpretation: ANSWER:

2.33; 2.042; Reject H0; The average number of hours until spoilage begins differs for preservatives A and B

POINTS: QUESTION TYPE: HAS VARIABLES:

1 Subjective Short Answer False

Chapter 10 - Inference from Small Samples STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/3/2019 12:30 PM 139. Do government employees take longer coffee breaks than private sector workers? That is a question that

interested a management consultant. To examine the issue, he took a random sample of ten government employees and another random sample of six private sector workers and measured the amount of time (in minutes) they spent in coffee breaks during the day. The results are listed below.

Assume that the population distributions are normal with equal variances. Do these data provide sufficient evidence at the 0.05 significance level to support the consultant's claim? Test statistic =

Give the t-value to two decimal places.

Critical Value(s) =

Give your answer to three decimal places.

Conclusion: Interpretation: Estimate with 95% confidence the difference in coffee breaks mean time between the two groups. Give the limits to two decimal places. ANSWER:

2.766; 2.10; Reject H0; These data support the consultant's claim; (1.37, 10.03)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/3/2019 12:59 PM 140. Two samples each of size 25 three-year-old children are taken from independent populations. The

populations are normally distributed with equal variances. The first sample has the mean of 35.5 and the

Chapter 10 - Inference from Small Samples

standard deviation of 3.0 while the second sample has the mean 33.0 and the standard deviation of 4.0. The pooled variance is _

. Give your answer to one decimal place.

The computed t-statistic is There are

. Give the t-value to two decimal places. degrees of freedom for this test.

The critical values for a two-tailed test of the null hypothesis of no difference in the population means at the = 0.05 level of significance . Give your answer to fourdecimal places. A two-tailed test of the null hypothesis of no difference would significance.

at the = 0.05 level of

The p-value for a two-tailed test with the obtained t-statistic is between If we were interested in testing against the one-tailed alternative that the null hypothesis would .

. at the

= 0.01 level of significance,

The p-value for a one-tailed test with the obtained t-statistic (in the hypothesized direction) is between . ANSWER: 12.5; 2.50; 48; −2.0106, 2.0106; be rejected; 0.01, 0.02; be rejected; 0.005, 0.01 POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:48 AM 141. A political analyst in Michigan surveys a random sample of registered Democrats and compares the results

with those obtained from a random sample of registered Republicans. This would be an example of an experimental design called a paired-difference or matched pairs design. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 142. In a paired-difference experiment, two samples of size n are being used. The number of degrees of freedom

associated with the paired-difference test is n − 1. a. True

Chapter 10 - Inference from Small Samples b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:49 AM 143. In comparing two population means when samples are matched pairs, the variable under consideration is d,

the difference between the corresponding sample values. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 144. The matched pairs experiment always produce a larger test statistic than the independent samples

experiment. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 145. A statistics professor wanted to test whether the grades on the statistics test were the same for upper and

lower classmen. The professor took a random sample of size 12 from each and conducted a test determining that the variances were equal. For this situation, the professor should use a matched pairs t-test. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/3/2019 1:22 PM 146. In comparing two population means when samples are dependent, x̄ d denotes the difference in the sample

means.

Chapter 10 - Inference from Small Samples a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/3/2019 1:52 PM 147. The number of degrees of freedom associated with the t-test, when the data are gathered from a matched

pairs experiment with 8 pairs, is 7. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 148. When comparing two population means using data that are gathered from a matched pairs experiment, the

test statistic for is Student t distributed with normally distributed.

degrees of freedom, provided that the differences are

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/3/2019 1:57 PM 149. A Marine drill instructor recorded the time in which each of 15 recruits completed an obstacle course both

before and after basic training. To test whether any improvement occurred, the instructor would use a tdistribution with 15 degrees of freedom. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 150. In comparing two population means of interval data, we must decide whether the samples are independent

Chapter 10 - Inference from Small Samples

(in which case the parameter of interest is to select the correct test statistic.

) or matched pairs (in which case the parameter is

) in order

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 151. A researcher is curious about the effect of sleep on students' test performances. He chooses 50 students and

gives each two tests: one given after four hours of sleep and one after eight hours of sleep. The test the researcher should use would be matched pairs t-test. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 152. A Marine drill instructor recorded the time in which each of 10 recruits completed an obstacle course both

before and after basic training. To test whether any improvement occurred, the instructor would use a tdistribution with 9 degrees of freedom. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 153. One reason for performing a paired-difference experiment is to: a. reduce the degrees of freedom b. allow one to use a larger value of c. reduce the quantity of information in the experiment d. reduce the variability in the sample data e. do none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice

Chapter 10 - Inference from Small Samples HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 154. Which of the following statements about matched-pairs sampling is correct? a. It is a procedure that matches each unit from population A with a "twin" from population B so that

any sample observation about a unit in population A automatically yields an associated observation about a unit in population B. b. It is designed to control for extraneous factors that might influence the characteristic being measured in addition to the variable under study. c. When testing the effectiveness of a new drug compared to a traditional one, each patient in an experimental group might be matched with a partner in a control group of the same age, weight, height, sex, occupation, medical history, lifestyle, and so on. d. All of the above. e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/3/2019 2:00 PM 155. The paired-difference t-test for the main difference between two populations assumes: a. that the populations are approximately normally distributed b. that the sample variances are equal c. that the sample means are equal d. all of the above e. none of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/3/2019 1:59 PM 156. If you wish to test the difference between the means of two-paired populations with samples of size 15

each, then the appropriate degrees of freedom is equal to: a. 29 b. 28 c. 15 d. 14 e. 12

Chapter 10 - Inference from Small Samples ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 157. In testing for differences between the means of two matched pairs populations, the null hypothesis is: a. b. c. d. e. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 158. If some natural relationship exists between each pair of observations that provides a logical reason to

compare the first observation of sample 1 with the first observation of sample 2, the second observation of sample 1 with the second observation of sample 2, and so on, the samples are referred to as: a. matched samples b. independent samples c. weighted samples d. random samples e. natural samples ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 159. The number of degrees of freedom associated with the t-test, when the data are gathered from a matched

pairs experiment with 10 pairs, is: a. 10 b. 20 c. 9

Chapter 10 - Inference from Small Samples d. 18 e. 14 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 160. The symbol x̄ d refers to: a. the difference in the means of two dependent populations b. the difference in the means of two independent populations c. the matched pairs differences d. the mean difference in the pairs of observations taken from two dependent samples e. the mean difference in the pairs of observations taken from two independent samples ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/3/2019 2:03 PM 161. The number of degrees of freedom associated with the t-test, when the data are gathered from a matched

pairs experiment with 19 pairs, is: a. 10 b. 20 c. 9 d. 18 e. 11 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/3/2019 2:05 PM 162. In what type of test is the variable of interest the difference between the values of the observations rather

than the observations themselves? a. A test for the equality of variances from two independent populations. b. A test for the difference between the means of two dependent populations. c. A test for the difference between the means of two independent populations.

Chapter 10 - Inference from Small Samples d. All of the above. e. None of these. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/3/2019 2:06 PM 163. In testing for differences between the means of two dependent populations where the variance of the

differences is unknown, the degrees of freedom are: a. n − 1 b. c. d. n − 2 e. n + 1 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:53 AM 164. In testing for differences between the means of two dependent populations the null hypothesis is: a. b. c. d. e. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 165. A test is being conducted to test the difference between two population means using data that are gathered

from a matched pairs experiment. If the paired differences are normal, then the distribution used for testing is the:

Chapter 10 - Inference from Small Samples a. normal distribution b. binomial distribution c. Student t-distribution d. F distribution e. paired distribution ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 166. We can design a matched pairs experiment when the data collected are: a. observational b. experimental c. controlled d. all the above e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/3/2019 2:07 PM 167. If we are testing for the difference between the means of 2 dependent populations (matched pairs

experiment) with samples of a. 29 b. 28 c. 16 d. 14 e. 13

and

, the number of degrees of freedom is equal to:

ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 2/4/2019 9:32 AM 168. A consumer was interested in determining whether there is a significant difference in the price charged for

tools by two hardware stores. The consumer selected five tools and recorded the price for each tool in each store. The following data was recorded:

Chapter 10 - Inference from Small Samples

Are the samples independent? Justify your answer. Assume the two population distributions are normal. Perform the appropriate test of hypothesis to determine whether there is a significant difference, on the average, in the price of tools between the two stores. Use = 0.05. Use the Data Analysis software if you prefer. Test Statistic = Reject Region: Reject H0 if |t| >

Give your answer to three decimal places.

Conclusion: One two stores.

conclude that there is a significant difference in the average price of tools between the

ANSWER:

No, since the pair of measurements for each tool are related.; 1.0; 2.776; Do not reject H0; cannot

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/3/2019 2:21 PM 169. In a study to compare average snowfall in two different cities, measurements were taken in each of the

cities for 10 randomly selected years. Snowfall, in inches, for the two cities are listed below.

Assume the two population distributions are normal. Use the data to determine if there is a significant difference in average snowfall in the two cities. Use a significance level of = 0.05.

Chapter 10 - Inference from Small Samples

Use the Data Analysis software if you prefer. Test Statistic =

Give your answer to three decimal places.

Reject Region: Reject H0 if |t| >

Give your answer to three decimal places.

Conclusion: The sample data support that ANSWER:

in the snowfalls.

−0.655; 2.262; Do not reject H0; there is no significant difference

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:53 AM 170. Two different brands of contact lenses are to be compared for length, in hours, of comfortable wear. The

lenses are available in any prescription. How might an experiment resulting in paired data be carried out?

How might an independent samples experiment be carried out?

Which method would you recommend, and why?

ANSWER:

Each brand of lens is tested on each of n people, each person wearing each type of lens for a predetermined length of time.; Each brand of lens is tested on n randomly selected people, each person only wearing one brand of lens.; The paired method. This method eliminates the variability in eye shape and prescription of different people. This allows the length of comfortable wear of the two brands to be distinguished easier.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic

Chapter 10 - Inference from Small Samples DATE CREATED: DATE MODIFIED:

2/4/2019 9:32 AM 2/4/2019 9:32 AM

171. A scientist is testing two different types of Secchi discs. This is an instrument used for determining water

clarity. The scientist takes a depth reading (in feet below the surface) with each disc at 8 different locations on a lake. The results of the 8 different locations for each Secchi disc are listed below.

Assume the two population distributions are normal. Determine if there is a significant difference in average depth reading for the two discs. Use a significance level of = 0.01. Use the Data Analysis software if you prefer. Test Statistic =

Give your answer to two decimal places.

Reject Region: Reject H0 if |t| >

Give your answer to three decimal places.

Conclusion: There ANSWER:

in average depth reading for two disks. 1.93; 3.499; Do not reject H0; is no significant difference.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/4/2019 6:38 AM 172. A researcher believes she has designed a keyboard that is more efficient to use than a standard keyboard. In

order to help decide if this is the case, typing speeds were taken for 8 different people on each keyboard. The lengths of time, in minutes, for each of the people to type a pre-selected manuscript are listed below.

Chapter 10 - Inference from Small Samples

Assume the two population distributions are normal. Use the data to determine if the original keyboard yields slower times. Use a significance level of = 0.05. Use the Data Analysis software if you prefer. Test Statistic =

Give your answer to three decimal places.

Reject Region: Reject H0 if |t| >

Give your answer to two decimal places.

Conclusion: The original keyboard ANSWER:

. 3.491; 1.89; Reject H0; DOES yield slower times

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/4/2019 7:00 AM 173. Five soft drink bottling companies have agreed to implement a time management program in hopes of

increasing productivity (measured in cases of soft drinks bottled per hour). The number of cases of soft drinks bottled per hour before and after the implementation of the program are listed below: Company

Assume the two population distributions are normal. Test whether the time management has been effective in increasing productivity. Calculate the value of the test statistic. Set up the appropriate rejection region for the hypotheses assuming . What is the appropriate conclusion? Use the Data Analysis software if you prefer. Test Statistic =

Give your answer to two decimal places.

Chapter 10 - Inference from Small Samples

Critical Value(s) =

Give your answer to three dicimal places.

Conclusion: One can conclude that the time management program

Find the approximate p-value using the t table. Enter (n1, n2) ANSWER:

−2.82; −2.132; Reject H0; HAS been effective in increasing production.; (.01, .025)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:54 AM 174. A new runner has decided to purchase a new pair of running shoes. He has narrowed his choices to two

brands, each of which would be appropriate for his use. His concern is whether there is a significant difference in the average wear between the two brands of shoes. He enlists a random sample of 6 veteran runners to test the shoes. Each runner wore each brand of shoes until it wore out. The following data was recorded, representing the number of weeks each runner used each pair of shoes: Runner

Assume the two population distributions are normal. The new runner used a paired-difference t-test for the analysis. Is this method appropriate? Justify your answer.

Perform the appropriate test of hypothesis to determine whether there is a significant difference in the average wear between the two brands of shoes. Use the 5% level of significance. Use the Data Analysis software if you prefer. Test Statistic = Reject Region: Reject H0 if |t| > Conclusion:

Give your answer to three decimal places. Give your answer to three decimal places.

Chapter 10 - Inference from Small Samples

One shoes.

that there is a significant difference in average wear length between the two brands of

Find a 95% confidence interval (CI) for the difference in average wear length between the two brands of shoes. CI =

Enter (n1, n2). Give your answer to three decimal places.

Based on this interval, one that there is a significant difference in average wear length between the two brands of shoes. ANSWER: Yes, since the samples are related. The pair of measurements for each jogger are definitely related.; .237; 2.571; Do not reject H0; CANNOT conclude; (−1.641, 1.974); CANNOT conclude POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 10:55 AM 175. A paired-difference experiment was conducted using 10 people who followed a diet program for 4 weeks.

Their weights before and after the program were recorded. Assume the two population distributions are normal. Test the null hypothesis H0: = 0 vs. Ha: 0 for = 0.05, = 0.35, and sd2 = 0.18. Give the approximate pvalue for the test. Use the Data Analysis software if you prefer. Test statistic =

Give your answer to three decimal places.

Find the approximate p-value using the t table. The p-value is between _

Conclusion: Find a 95% confidence interval for

Give your answer to three decimal places. ANSWER:

2.609; 0.02, 0.05; Reject H0; (0.046, 0.654)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM

Chapter 10 - Inference from Small Samples DATE MODIFIED:

4/4/2019 8:58 AM

176. An advertisement for Meijer, a supermarket chain in Michigan, claims that Meijer has had consistently

lower prices than four other full-service supermarkets. As part of a survey conducted by an "independent market basket price-checking company", the average weekly total, based on the prices of approximately 95 items, is given for two different supermarket chains recorded during 4 consecutive weeks in a particular month.

Assume the two population distributions are normal. Is there a significant difference in the average prices for these two different supermarket chains? Test at = 0.05. What is the approximate p-value for the test? Construct a 95% confidence interval for the difference in the average prices for the two supermarket chains. Test Statistic =

Give your answer to one decimal place.

Reject Region: Reject H0 if |t| >

Give your answer to three decimal places.

Conclusion: One

conclude that the means are different.

Find the approximate p-value using the t table.

P-value =

Enter (n1, n2)

What is the 95 % confidence interval? (CI) CI = ANSWER:

Enter (n1, n2). Give your answer to two decimal places. −3.0; 3.182; Do not reject H0; cannot; (.05, .10); (-34.56, 1.03)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 11:01 AM 177. The general manager of a chain of fast food chicken restaurants wants to determine how effective their

promotional campaigns are. In these campaigns "20% off" coupons are widely distributed. These coupons are only valid for one week. To examine their effectiveness, the executive records the daily gross sales (in $1,000s) in one restaurant during the campaign and during the week after the campaign ends. The data is shown below.

Chapter 10 - Inference from Small Samples

Assume the two population distributions are normal. Can they infer at the 0.05 significance level that sales increase during the campaign? Use the Data Analysis software if you prefer. Test statistic =

Give your answer to three decimal places.

Critical Value(s) =

Give your answer to three decimal places.

Conclusion: Interpretation: Estimate with 95% confidence the mean difference. Give your answer to three decimal places. ANSWER:

4.111; 1.943; Reject H0; There is a sufficient evidence that sales increase during the campaign; (0.387, 1.527)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/4/2019 9:55 AM 178. Ten functionally illiterate adults were given an experimental one-week crash course in reading. Each of the

ten adults was given a reading test prior to the course and another test after the course. The results are shown below.

Assume the two population distributions are normal. Is there enough evidence to infer at the 0.05 significance level that the reading scores have improved?

Chapter 10 - Inference from Small Samples

Use the Data Analysis software if you prefer. Test statistic =

Give your answer to two decimal places.

Critical Value(s) =

Give your answer to three decimal places.

Conclusion: Interpretation: Estimate the mean improvement with 95% confidence. Give your answer to two decimal places. ANSWER:

4.29; 1.833; Reject H0; The reading scores have improved at the 0.05 significance level; (4.54, 14.66)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/4/2019 10:27 AM 179. Automobile insurance appraisers examine cars that have been involved in accidental collisions to assess the

cost of repairs. An insurance executive is concerned that different appraisers produce significantly different assessments. In an experiment 10 cars that have recently been involved in accidents were shown to two appraisers. Each assessed the estimated repair costs. These results are shown below.

Assume the two population distributions are normal. Can the executive conclude at the 0.05significance level that the appraisers differ in their assessments? Use the Data Analysis software if you prefer.

Chapter 10 - Inference from Small Samples

Test statistic = Critical Value(s) =

Give your answer to two decimal places. Give your answer to two decimal places.

Conclusion: Interpretation: ANSWER:

1.802; (−2.262, 2.262); Do not reject H0; The appraisers DO NOT differ in their assessments at the 0.05 significance level

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/17/2019 11:01 AM 180. A marketing consultant was in the process of studying the perceptions of married couples concerning their

weekly food expenditures. He believed that the husband's perception would be higher than the wife's. To judge his belief, he takes a random sample of ten married couples and asks each spouse to estimate the family food expenditure (in dollars) during the previous week. The data are shown below.

Assume the two population distributions are normal. Can the consultant conclude at the 0.05 significance level that the husband's estimate is higher than the wife's estimate? Use the Data Analysis software if you prefer. Test statistic = Critical Value(s) = Conclusion: Interpretation:

Give your answer to three decimal places. Give your answer to three decimal places.

Chapter 10 - Inference from Small Samples

Estimate with 95% confidence the population mean difference. Give your answer to one decimal place. ANSWER:

2.776; 1.833; Reject H0; The husband's estimate is higher than the wife's estimate at the 0.05 significance level; (5.9, 58.1)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:32 AM DATE MODIFIED: 4/4/2019 11:01 AM 181. The test statistic used to test hypotheses about the population variance

, which is chi-

squared distributed with n − 1 degrees of freedom when the population is normally distributed with variance equal to . a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/17/2019 11:04 AM 182. The t distribution with n − 1 degrees of freedom is used when testing a null hypothesis for the population

variance. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/17/2019 11:03 AM 183. If you wish to test

vs.

critical value to be used is 23.685. a. True b. False ANSWER: POINTS:

True 1

at the .05 level of significance using a sample of 15 observations, the

Chapter 10 - Inference from Small Samples QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 184. If you wish to test

vs.

at the .05 level of significance using a sample of 20 observations,

the critical values to be used are 32.852. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 185. For a given level of significance, increasing the sample size will tend to increase the chi-square critical

value used in testing the null hypothesis about a population variance. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 186. The chi-squared critical value

based on 6 df denotes the number on the measurement axis such that

10% of the area under the chi-squared curve with 6 degrees of freedom lies to the right of

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 8:04 AM th

187. The 5 percentile of a chi-square distribution with 10 degrees of freedom is equal to 4.3903. a. True b. False ANSWER: False

Chapter 10 - Inference from Small Samples POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 8:07 AM 188. The 90th percentile of a chi-square distribution with 15 degrees of freedom is equal to 22.3072. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 8:08 AM 189. The area under a chi-squared curve with 10 degrees of freedom, which is captured between the critical

values

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 190. The chi-square distribution can be used in constructing confidence intervals and carrying out hypothesis

tests regarding the value of the population variance. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 8:17 AM 191. The chi-square distribution is skewed to the left (negatively skewed), but as degrees of freedom increase, it

approaches the shape of the binomial distribution. a. True b. False ANSWER:

False

Chapter 10 - Inference from Small Samples POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 192. The area to the right of a chi-square variable is 0.025. For 5 degrees of freedom, the critical value is 11.143. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 8:55 AM 193. A right-tailed area in the chi-square distribution equals 0.05. For 8 degrees of freedom, the critical value

equals 13.362. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 8:56 AM 194. The chi-square distribution is: a. symmetric around zero b. positively skewed c. negatively skewed d. mound-shaped e. positively skewed and mound-shaped ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 8:57 AM 195. The shape of the chi-square distribution depends on: a. the population variance b. the number of its degrees of freedom

Chapter 10 - Inference from Small Samples c. the population mean d. all of the above e. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 8:58 AM 196. The sampling distribution of the quantity

is:

a. an F distribution b. a chi-square distribution c. a normal distribution d. a t distribution e. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 8:59 AM 197. A random sample of 20 observations is selected from a normally distributed population. The sample

variance is 12. In the 95% confidence interval for the population variance, the upper limit will be: a. 6.940 b. 7.564 c. 22.536 d. 25.599 e. 27.392 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 198. In a hypothesis test for the population variance, the hypotheses to be tested are

vs. . If the sample size is 20 and the test is being carried out at the 10% level of significance, the null hypothesis will be rejected if:

Chapter 10 - Inference from Small Samples a. b. c. d. e. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 9:02 AM 199. The sampling distribution used to make inferences about a single population variance is: a. a normal distribution b. a t distribution c. an F distribution d. a chi-square distribution e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 200. If a hypothesis test is to be conducted regarding a population variance, then the critical value of the test will

be obtained using the: a. normal distribution b. t distribution with n − 1 degrees of freedom c. chi-square distribution with n − 1 degrees of freedom d. binomial distribution e. t distribution with n + 1 degrees of freedom ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM

Chapter 10 - Inference from Small Samples DATE MODIFIED: 4/17/2019 11:05 AM 201. If you are testing

vs.

using a sample of 15 observation and a significance level equal

to .05, then the critical value of the test is: a. 1.7613 b. 6.6450 c. 23.685 d. 4.867 e. 5.319 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 202. Which of the following statements is true with regard to a hypothesis test for a population variance

. a. The null hypothesis is stated in terms of b. The chi-square distribution is used to determine the critical value. c. The critical value increases as the sample size increases for a given level of significance. d. All of the above. e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 9:05 AM 203. In testing

vs.

the following sample data were recorded: 5.0, 6.1, and 11.1. Then, the value

of the test statistic is: a. 10.570 b. 5.285 c. 7.400 d. 6.714 e. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False

Chapter 10 - Inference from Small Samples DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 204. In testing

vs.

the following sample data were recorded: 11.5, 6.5, and 5.4. Then, the p-value

of the test is: a. between .05 and .10 b. between .10 and .20 c. between .03 and .05 d. greater than .20 e. less than .03 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 9:08 AM 205. A random sample of 25 observations is selected from a normally distributed population. The sample

variance is 10. In the 95% confidence interval for the population variance, the upper limit will be: a. 17.110 b. 6.097 c. 17.331 d. 19.353 e. 11.842 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 206. In a hypothesis test for the population variance, the hypotheses are

vs. . If the sample size is 20 and the test is being carried out at the 5% level of significance, the null hypothesis will be rejected if: a. b. c.

Chapter 10 - Inference from Small Samples d. e. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 9:12 AM 207. In a hypothesis test for the population variance, the hypotheses are

vs. . If the sample size is 15 and the test is being carried out at the 10% level of significance, the rejection region will be: a.

< 6.571 or

> 23.685

< 7.790 or

> 21.064

< 8.547 or

> 22.307

< 7.261 or

< 24.996

< 6.431 or

> 21.653

b. c. d. e. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 9:14 AM 208. The chi-square distribution is: a. symmetrical about 0 b. positively skewed ranging between 0 and c. symmetrical around d. negatively skewed ranging between e. mound-shaped ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM

and 0

Chapter 10 - Inference from Small Samples DATE MODIFIED: 4/15/2019 9:17 AM 209. Like that of the Student t distribution, the shape of the chi-square distribution depends on: a. the population size b. the number of its degrees of freedom c. the population standard deviation d. whether the population is unimodal or bimodal e. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 9:18 AM 210. The statistic

is chi-square distributed with n − 1 degrees of freedom only if:

a. the population is normally distributed with variance equal to b. the sample is normally distributed with variance equal to c. the sample has a Student t distribution with degrees of freedom equal to n − 1 d. all of the above e. none of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/17/2019 11:06 AM 211. A random sample of size 20 taken from a normally distributed population resulted in a sample variance of

32. The lower limit of a 90% confidence interval for the population variance would be: a. 52.185 b. 20.375 c. 20.170 d. 54.931 e. 29.655 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM

Chapter 10 - Inference from Small Samples 212. A random sample of size 25 taken from a normally distributed population resulted in a sample standard

deviation of a 0.93054. The lower and upper limits of a 99% confidence interval for the population variance would be: a. 9.886 and 45.559 b. 3.144 and 6.750 c. 0.678 and 1.449 d. 0.456 and 2.102 e. 1.493 and 6.430 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 213. The variability in a scientist's measuring equipment was observed for a random sample of 26 test runs from

a normal distribution. The sample yielded a variance of 33. Estimate the population variance using a 95% confidence interval.

ANSWER:

Enter (n1, n2). Give your answer to two decimal places. (20.3, 62.88)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 9:23 AM 214. A car salesperson tries to convince customers buying a new Honda Accord that the gas mileage varies by

only 2 miles per gallon when driving in town and on the highway. The customer found, for 14 randomly chosen tanks of gas, the gas mileage to vary by 2.8 miles per gallon. Do the customer's results contradict the salesperson's claim? Test the relevant hypotheses at the 0.05 level of significance. Assume the sample comes from a normal population. Test Statistic =

Give your answer to two decimal places.

Reject Region:

Enter (n1, n2). Give your answer to four decimal places.

Conclusion: Interpretation: ANSWER:

25.48; 5.0088, 24.7356; Reject H0; The customer's results CONTRADICT the salesperson's claim.

POINTS:

Chapter 10 - Inference from Small Samples QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 10:09 AM 215. A pasta company would like to know the variability in the shelf life of their product. A random sample of

20 packages of pasta yielded a standard deviation of 5 days. Estimate the population variance using a 90% confidence interval. Assume the distribution is normal.

ANSWER:

Enter (n1, n2). Give your answer to two decimal places. (15.76, 46.95)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 10:12 AM 216. A city bus driver claims that the route from the Canyon Crest Town Center to the University of California,

Riverside never varies more than 1.3 minutes. A random sample of 18 trips yielded a variance of 1.26 minutes2. It is of interest to determine if the sample data present sufficient evidence to reject the driver's claim. Assume the sample comes from a normal population. Calculate the value of the test statistic. What is the appropriate conclusion at the 0.05 level of significance? Test Statistic =

Give your answer to four decimal places.

Reject Region: Reject H0 if

Give your answer to two decimal places.

Conclusion: One ANSWER:

conclude that the route varies by more than 1.3 minutes. 12.6746; 27.59; Do not reject H0; CANNOT

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 10:17 AM 217. Butch's Dog Kennel boards and trains dogs. There are different breeds and numbers of dogs at the kennel

each month. Butch would like to know the variability in the pounds of dog food used each month. A random sample of 12 months yielded the pounds of dog food listed below.

Chapter 10 - Inference from Small Samples

1500, 2300, 2090, 3000, 1980, 1760, 1660, 2470, 3500, 2870, 1300, 1810 Use the data to estimate the population variance using a 99% confidence interval. Assume the distribution is normal. Use the Data Analysis software if you prefer.

ANSWER:

Enter (n1, n2). Round your answer to whole numbers, no commas in numerals. (181541, 1865944)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/17/2019 11:08 AM 218. An aircraft manufacturer requires bolts that are part of the landing gear assembly to have a mean diameter

of 1.1 inches with a variance of no more than 0.04 inches2. The bolts are purchased from an outside supplier. A random sample of 30 bolts from a recently received shipment yielded a variance of 0.054 inches2. Assume the distribution is normal. Should the shipment be returned? Perform the appropriate test of hypothesis using = 0.05. Test Statistic =

Give your answer to two decimal places.

Reject Region: Reject H0 if

Give your answer to three decimal places.

Conclusion: Conclusion: ANSWER:

39.15; 42.557; Do not reject H0; DO NOT send back shipment.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 10:27 AM 219. A random sample of size n = 7 from a normal population produced these measurements:

2.1, 4.3, 2.4, 2.7, 4.0, 3.5, 3.6. Calculate the sample variance,

Give your answer to three decimal places

Chapter 10 - Inference from Small Samples

Construct a 95% confidence interval (CI) for the population variance, CI =

Enter (n1, n2). Give your answer to four decimal places.

Test

using

Test Statistic =

Give your answer to two decimal places.

Critical Value(s) =

= 0.05. State your conclusions.

Give your answer to four decimal places.

Conclusion: There is

_ to indicate that

is different from 0.8.

What is the approximate p-value for the test? Give your answer to two decimal places. ANSWER:

.699; (.2903, 3.3897); 5.24; 1.2373, 14.4494; Do not reject H0; INSUFFICIENT evidence; .97

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 10:52 AM 220. A precision instrument is guaranteed to read accurately to within 2 units. A sample of four instrument

readings on the same object yielded the measurements 360, 358, 358, and 362. Test the null hypothesis that = 0.7 against the alternative > 0.7. Assume the distribution is normal. Use = 0.05. Test statistic =

Give our answer to three decimal places.

Critical Value(s) =

Give your answer to two decimal places.

Conclusion: Interpretation: Find a 90% confidence interval for the population variance. Enter (n1, n2). Give your answer to two decimal places. ANSWER:

22.449; 7.81; Reject H0; The variance is greater than 0.49 at the significance level of 0.05; (1.408, 31.264)

Chapter 10 - Inference from Small Samples POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 11:04 AM 221. Consider the hypotheses H0:

= 20 vs. Ha: > 20. Assume that math scores on a 25-point quiz for a random sample of 5 students were drawn from a normal population. These were: 18, 16, 10, 13, and 23. Test the hypotheses at the 10% significance level. Test statistic =

Give your answer to two decimal places.

Critical Value(s) =

Give your answer to three decimal places.

Conclusion: Interpretation: Estimate the population variance with 90% confidence. Enter (n1, n2). Give your answer to one decimal place. ANSWER:

4.90; 7.779; Do not reject H0; The population variance is not differ from 20 at the significance level 0.1; (10.3, 137.9)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 11:21 AM 222. A financial analyst is concerned with the risk associated with a portfolio of stocks. She draws a random

sample of nine monthly returns (expressed as a percentage of the initial investment). These data follow: 2, 5, −6, 10, 1, 2, −3, 0, and 7. Assume the normal distribution. Find a 95% confidence interval estimate of the population variance.

ANSWER:

Enter (n1, n2). Give your answer to two decimal places. (10.95, 88.08)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic

Chapter 10 - Inference from Small Samples DATE CREATED: DATE MODIFIED:

2/4/2019 9:33 AM 4/17/2019 11:09 AM

223. The grades of a sample of 10 students, selected at random from a large population, are 71, 86, 75, 63, 92,

70, 81, 59, 80, and 90. Give your answers to three decimal places. Compute the sample variance.

Construct a 90% confidence interval estimate for the population variance. Enter (n1, n2). Construct a 90% confidence interval estimate for the population standard deviation. Enter (n1, n2).

Can we infer at the 90% confidence that the population variance is significantly less than 100? Test statistic = Critical Value(s) = Conclusion: Interpretation: ANSWER:

123.122; (65.495, 333.252); (8.093, 18.255); 11.081; 4.168; Do not reject H0; The population variance IS NOT significantly less than 100

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 11:58 AM 224. In testing the equality of two population variances, when the populations are normally distributed, the 5%

level of significance has been used. To determine the rejection region, you will refer to the F table corresponding to an upper-tail area of 0.025. a. True b. False ANSWER:

True

Chapter 10 - Inference from Small Samples POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 225. We can use either the z-test or the t-test to determine whether two population variances are equal. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 226. The value of F with area 0.05 to its right for a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM

= 6 and

= 9 is 3.37.

227. The value of F that locates an area 0.01 in the upper tail of the F distribution for

= 15 and

= 10 is

3.80. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 12:01 PM 228. In a one-tailed test of the equality of two population variances, the F-test statistic is calculated by placing

the larger sample variance in the numerator. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False

Chapter 10 - Inference from Small Samples HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 229. If two population variances have been tested and found to be equal, then it is reasonable to conclude that

the two random samples selected from the two populations have equal variances. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 230. In testing

vs.

the null hypothesis will be rejected if the ratio

is substantially longer

than 1.0. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 231. A two-tailed test for two population variances could have the null hypothesis to be written as

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 232. In testing

vs.

the larger the sample sizes from the two populations, the smaller will be the

chance of committing a Type I error. a. True b. False ANSWER:

False

Chapter 10 - Inference from Small Samples POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 233. In testing

vs.

the critical value is determined from the F distribution table with an upper

tail area equal to half the value of the level of significance. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 12:02 PM 234. In testing

vs.

and

then the calculated value of the test statistic is F = 1.60.

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 235. The F distribution is used in testing

vs.

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 12:03 PM 236. In testing a. True b. False

vs.

the F-test statistic is calculated as F =

Chapter 10 - Inference from Small Samples ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 12:05 PM 237. When the necessary conditions are met, a two-tailed test is being conducted at

The two sample variances are region is F > 2.20.

= 0.05 to test

, and the sample sizes are

. The rejection

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 12:26 PM 238. We can use either the χ2-test or the F-test to determine whether two population variances are equal. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 12:36 PM 239. In testing for the equality of two population variances, when the populations are normally distributed, the

5% level of significance has been used. To determine the rejection region, it will be necessary to refer to the F table corresponding to an upper-tail area of 0.05. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 240. The test statistic employed to test

, which is F distributed with

Chapter 10 - Inference from Small Samples

degrees of freedom, provided that the two populations are F distributed. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 12:41 PM 241. When the necessary conditions are met, a two-tailed test is being conducted at

The two sample variances are value of the test statistic will be F = 2.

, and the sample sizes are

= 0.05 to test

. The calculated

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 12:46 PM 242. When comparing two population variances, we use the ratio a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM

rather than the difference

243. The F-test used for testing the difference in two population variances is always a one-tailed test. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM

Chapter 10 - Inference from Small Samples 244. The test for the equality of two population variances assumes that each of the two populations is normally

distributed. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 245. The F distribution is symmetric. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 12:48 PM 246. The assumption(s) for

to have an F distribution is (are):

a. random samples are drawn from each of two normal populations b. the samples are independent c. the variability of the measurements in the two populations is the same and can be measured by a

common variance, d. all of the above e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 12:49 PM 247. Which of the following is not a property of the F distribution? a. F distributions are nonsymmetrical. b. F distributions have (n − 1) degrees of freedom. c. F can assume only positive values. d. There are many F distributions and each has a different shape. e. F distributions are nonsymmetrical and F can assume only positive values. ANSWER: b

Chapter 10 - Inference from Small Samples POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/17/2019 11:11 AM 248. The sampling distribution of the ratio of two independent sample variances selected randomly from normal

populations with equal variances is: a. a normal distribution b. a t distribution c. an F distribution d. a binomial distribution e. a chi-square distribution ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 249. For an F distribution, the number of degrees of freedom for the denominator: a. must be larger than the number of degrees of freedom for the numerator b. must be equal to the number of degrees of freedom for the numerator c. must be smaller than the number of degrees of freedom for the numerator d. can be larger, smaller, or equal to the number of degrees of freedom for the numerator e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 12:51 PM 250. If two random samples of 10 and 12 observations produced sample variances equal to 7.50 and 3.20,

respectively, then the calculated value of the test statistic when testing a. 7.50 b. 3.20 c. 10.70 d. 2.34 e. 7.82 ANSWER:

vs.

is equal to:

Chapter 10 - Inference from Small Samples POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 12:53 PM 251. When testing

vs.

two random samples of sizes 10 and 8, respectively, are used. The

calculated value of the test statistic is found to be equal to 2.22. Which of the following statements is true? a.

must be rejected at

cannot be rejected at . c. There is sufficient evidence at d.

cannot be rejected at e. None of these.

to conclude that a difference in the population variances exist.

ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 252. Which of the following formats for the null hypothesis is acceptable when testing whether two population

variances are equal? a. b. c. d. all of the above e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 12:54 PM 253. Which of the following distributions is used in testing a. Chi-square distribution

vs.

Chapter 10 - Inference from Small Samples b. Normal distribution c. F distribution d. t distribution e. Chi-square distribution and Normal distribution ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/17/2019 11:12 AM 254. In testing

vs.

, which of the following statements is true?

a. The larger sample variance must be used as the numerator of the F-test statistic. b. The level of significance needs to be doubled before finding the critical value in the F-table. c. The alternative hypothesis must contain equality. d. You are free to decide which of the two populations you want to call "Population 1." e. The level of significance needs to be doubled before finding the critical value in the F-table and the

alternative hypothesis must contain the equality. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 12:56 PM 255. The F distribution is the sampling distribution of the ratio of: a. two normal population variances b. two normal population means c. two sample variances provided that the samples are independently drawn from two normal

populations with equal variances d. two sample variances provided that the sample sizes are large e. none of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 12:57 PM 256. Which of the following statements is false for an F distribution?

Chapter 10 - Inference from Small Samples a. Variables that are F distributed range from 0 to

. b. The exact shape of the distribution is determined by two numbers of degrees of freedom. c. Degrees of freedom for the denominator cannot be smaller than the degrees of freedom for the numerator. d. Degrees of freedom for the numerator can be smaller than the degrees of freedom for the denominator. e. Degrees of freedom for the numerator can be larger or equal to the degrees of freedom for the denominator. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 1:14 PM 257. The sampling distribution of the ratio of two sample variances

is said to be F distributed provided

that: a. the samples are independent b. the populations are normal with equal variances c. the samples are dependent and their sizes are large d. the samples are independently drawn from two normal populations e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 258. When testing for the difference between two population variances with sample sizes of

the numbers of degrees of freedom are: a. 8 and 10 b. 7 and 9 c. 2 and 18 d. 18 and 2 e. 9 and 11 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 1:15 PM

and

Chapter 10 - Inference from Small Samples 259. Which of the following statements is correct regarding the percentile points of the F distribution? a. b. c. d. e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 1:17 PM 260. In testing for the equality of two population variances, when the populations are normally distributed, the

10% level of significance has been used. To determine the rejection region, it will be necessary to refer to the F table corresponding to an upper-tail area of: a. 0.90 b. 0.05 c. 0.20 d. 0.10 e. 0.85 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 261. In constructing a 90% interval estimate for the ratio of two population variances,

, two independent samples of sizes 40 and 60 are drawn from the populations. If the sample variances are 515 and 920, then the lower confidence limit is: a. 0.349 b. 0.341 c. 0.890 d. 0.918 e. 0.245 ANSWER: POINTS:

a 1

Chapter 10 - Inference from Small Samples QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 1:25 PM 262. The statistical distribution used for testing the difference between two population variances is the: a. Student's t distribution b. standard normal distribution c. binomial distribution d. F distribution e. chi-square distribution ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/17/2019 11:15 AM 263. The test for the equality of two population variances is based on the: a. difference between the two sample variances b. ratio of the two sample variances c. difference between the two population variances d. difference between the two sample variances divided by the difference between the two population

variances e. difference between the two population variances divided by the two sample variances ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 2/4/2019 9:33 AM 264. A stylist realizes that the quicker she can give a permanent, the happier the customer will be. She has made

a slight adjustment to her traditional routine in hopes of reducing the time required. A random sample of 13 permanents from before and 16 after were timed. The results of the tests are listed below. Assume the two samples were taken from normal populations with equal variances.

Do the sample variances present sufficient evidence to indicate that the population variance before is greater than the variance after? Test the appropriate hypotheses using a significance level of 0.05. Interpret your results.

Chapter 10 - Inference from Small Samples

Test Statistic =

Give your answer to three decimal places.

Reject Region: Reject H0 if F >

Give your answer to two decimal places.

Conclusion: There is

_ to indicate that the population variance before is greater than the variance after.

Construct a 95% confidence interval (CI) for CI =

Enter (n1, n2). Give your answer to two decimal places.

Find the approximate p-value for the test. Enter (n1, n2). ANSWER:

3.357; 2.48; Reject H0; SUFFICIENT evidence; (1.13, 10.66); (.01, .025)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 1:35 PM 265. Two soft drink machines dispense liquids of 10 ounces, on the average. The question is whether the two

machines are equally consistent (i.e., equally variable) in the dispensing of the liquid. To answer this question, a sample of size 10 was obtained from each machine and the sample standard deviations were computed to be = 1.87 ounces and = 1.25 ounces. Assume the two samples were taken from normal populations. Perform the appropriate test for equality of variances using = 0.05. Test Statistic =

Give your answer to three decimal places.

Reject Region: Reject H0 if F>

Give your answer to two decimal places.

Conclusion: One conclude that there is a significant difference in the variability of liquid dispensed between the two machines. ANSWER:

2.238; 4.03; Do not reject H0; CANNOT

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:33 AM

Chapter 10 - Inference from Small Samples DATE MODIFIED:

4/15/2019 1:42 PM

266. The printing time of a weekly magazine was studied using two different machines,

and . Eight different magazines were randomly assigned to each of the two printing machines, and produced standard deviations = 2.08, and = 1.66 for machines and , respectively. Assume the required assumptions are met and use = 0.05 to determine if the variances for the two machines are different. Give your answers to two decimal places.

Test Statistic = Reject Region: Reject H0 if F > Conclusion: There is

_ to indicate a difference in the population variances.

ANSWER:

1.57; 4.99; Do not reject H0; INSUFFICIENT evidence POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 1:44 PM 267. Independent random samples from two normal populations produced the variances listed here:

Do the data provide sufficient evidence to indicate that Test Statistic =

differs from

= .05.

Give your answer to three decimal places.

Reject Region: Reject H0 if F >

Give your answer to two decimal places.

Conclusion: One

? Test using

conclude that the variances are different.

Find the approximate p-value for the test. Enter (n1, n2).

Chapter 10 - Inference from Small Samples

Develop a 95% confidence interval for CI = ANSWER:

Enter (n1, n2). Give your answer to four decimal places. 1.846; 2.33; Do not reject H0; CANNOT; (.10, .20); (.7933, 4.4447)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/17/2019 11:16 AM 268. The average total SAT scores (verbal plus math) were recorded for two groups of students: one group

planning to major in engineering and one group planning to major in language/literature.

To use the two-sample t-test with a pooled estimate of , you must assume that the two population are normal and their variances are equal. Test this assumption using the F test for equality of variances using = 0.05. Test Statistic =

Give your answer to three decimal places.

Reject Region: Reject H0 if F >

Give your answer to two decimal places.

Conclusion: One

conclude that the variances are different.

What is the approximate p-value for the test? Give your answer to three decimal places. ANSWER:

1.057; 2.86; Do not reject H0; CANNOT; .0.916

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 1:54 PM 269. An experimenter is concerned that variability of responses using two different experimental procedures

may not be the same. He randomly selects two samples of 16 and 14 responses from two normal populations

Chapter 10 - Inference from Small Samples

and gets the statistics: s12 = 55, and s22 = 118, respectively. Do the sample variances provide enough evidence at the 0.1 significance level to infer that the two population variances differ? Give your answers to three decimal places. Test statistic = Critical Value(s) = Conclusion: Interpretation: Estimate with 90% confidence the ratio of the two population variances.

ANSWER:

0.466; 0.408; Do not reject H0; The two population variances DO NOT differ at the 0.1 significance level; (0.184, 1.141)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/15/2019 2:02 PM 270. A statistician wants to test for the equality of means in two independent samples drawn from normal

populations of people enrolled in a diet program. However, he will not perform the equal-variance t-test of the difference between the population means if the condition necessary for its use is not satisfied. The number of pound lost at the completion of the program data follow:

Can the statistician conclude at the 5% significance level that the required condition is not satisfied? Test statistic = Critical Value(s) =

Give your answer to three decimal places. Give your answer to three decimal places.

Conclusion: Interpretation: Estimate with 95% confidence the ratio of the two population variances.

Chapter 10 - Inference from Small Samples

Give your answer to four decimal places. ANSWER:

0.108; 0.207; Reject H0; The required condition IS NOT satisfied at the 5% significance level; (0.0257, 0.5206)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/16/2019 5:13 AM 271. A food processor wants to compare two preservatives for their effects on retarding spoilage. Suppose 16

Assume the two samples were taken from normal populations. Calculate the value of the test statistic for testing the equality of the population variances, and write the proper conclusion for = 0.05. Test statistic =

Give your answer to three decimal places.

Critical Value(s) =

Give your answer to two decimal places.

Conclusion: Interpretation: Develop the 95% confidence interval estimate of the ratio of the two population variances. Give your answer to three decimal places. ANSWER:

0.596; 2.86; Do not reject H0; The population variances for preservatives A and B are equal at the 5% significance level; (0.208, 1.706)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:33 AM DATE MODIFIED: 4/16/2019 5:21 AM

Chapter 11 - The Analysis of Variance 1. Analysis of variance (ANOVA) can be used to compare more than two population means. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/4/2019 8:59 AM 2. One of the assumptions underlying analysis of variance for a completely randomized design is that the

observations within each population are normally distributed with unequal variance. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 3. In analysis of variances, the sum of squares for treatments (SST) is zero when all the sample means are equal. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 4. Given the significance level 0.05, the F-value for the degrees of freedom a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM

=5 and

= 8, is 4.82.

5. In analysis of variances, the sum of squares for error (SSE) is zero when all the sample variances are equal to

zero. a. True

Chapter 11 - The Analysis of Variance b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/4/2019 9:14 AM 6. The analysis of variance (ANOVA) technique analyzes the variance of the data to determine whether

differences exist between the population variances. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 7. The equation: Total SS = SST + SSB + SSE, applies to the completely randomized design (one-way ANOVA

model). a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 8. Two samples of ten each from the male and female workers of a large company have been taken. The data

involved the wage rate of each worker. To test whether there is any difference in the average wage rate between male and female workers, the most likely ANOVA design to fit this test situation is the randomized block design. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 9. In ANOVA, a factor is an independent variable whose values are controlled and varied by the experimenter,

while a level is the intensity setting of a factor.

Chapter 11 - The Analysis of Variance a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 10. Randomization is a procedure that eliminates the effects of extraneous factors during an experiment, even

prior to the administration of treatments, by creating blocks of experimental units so that all units within any one block are as alike as possible with respect to these factors. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 11. The completely randomized design is an experimental plan that creates one treatment group for each

treatment and then randomly assigns each experimental unit to one of these groups. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 12. The analysis of variance, ANOVA, is best described as a statistical technique designed to test whether the

means of more than two quantitative populations are equal. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 13. One-factor or one-way ANOVA is one of several versions of the analysis of variance, which controls

extraneous factors by using the randomized group design.

Chapter 11 - The Analysis of Variance a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 14. Two-factor or two-way ANOVA is one of several versions of the analysis of variance, which controls

extraneous factors by using the randomized block design. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 15. In the analysis of variance, explained variation equals the treatments means square in one-way ANOVA. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 16. The F statistic is the arithmetic mean of two or more means. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 17. In the analysis of variance, the ANOVA table is a summary table that shows, for each source of variation,

the sum of squares, the degrees of freedom, and the ratio of the sum of squares to the associated degrees of freedom (called the mean square) and also shows the F statistic. a. True

Chapter 11 - The Analysis of Variance b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 18. In the analysis of variance, the sum of all samples' sums of squared deviations of individual observations

from their sample mean equals the error mean square. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 19. In one-way ANOVA, there is a single factor of interest but there may be multiple levels of the factor. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 20. The term one-way ANOVA refers to the fact that in conducting the test, there is only one way to partition

the total sum of squares. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 21. The one-way ANOVA assumes that the population means are equal. a. True b. False ANSWER: False

Chapter 11 - The Analysis of Variance POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 22. In a one-way ANOVA, the total variation in the data across the various factor levels can be partitioned into

two parts: the between samples variation (called the sum of squares for treatments) and the within samples variation (called the sum of squares for error). a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 23. In a one-way ANOVA, the null hypothesis is written in terms of the population variances. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 24. The one-way ANOVA requires that the sample sizes are all equal. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 25. In a one-way ANOVA, total SS is equal to 12,345, and SST is equal to 10,685, then SSE = 1,660. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False

Chapter 11 - The Analysis of Variance HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 26. In a one-way ANOVA, the following null and alternative hypotheses are appropriate:

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/4/2019 9:35 AM 27. In a one-way ANOVA, if the sum of squares for error (SSE) is large relative to the sum of squares for

treatments (SST), this is an indication that the population means are likely to be different. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 28. In a one-way ANOVA, if the null hypothesis that all population means are equal is rejected, then we can

conclude that the alternative hypothesis is true and that all population means differ. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 29. The sum of squares for treatments, SST, achieves its smallest value (zero) when all the sample means are

equal. a. True b. False ANSWER:

True

Chapter 11 - The Analysis of Variance POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 30. The F-test of the analysis of variance requires that the populations be normally distributed with equal

variances. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 31. In one-way ANOVA, the test statistic is defined as the ratio of the mean square for error (MSE) and the

mean square for treatments (MST); namely, F = MSE / MST. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/10/2019 4:02 AM 32. The calculated value of F in a one-way ANOVA is 7.88. The numerator and denominator degrees of

freedom are 3 and 9, respectively. The most accurate statement to be made about the p-value is that p-value < 0.01. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 33. The numerator or MST degrees of freedom are 3 and the denominator or MSE degrees of freedom are 18.

The total number of observations in the completely randomized design must equal 20. a. True b. False ANSWER:

False

Chapter 11 - The Analysis of Variance POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 34. One-way ANOVA is used when: a. analyzing the difference between more than two population means b. analyzing the difference between two population variances c. analyzing the difference between two sample means d. analyzing the difference between two population proportions e. none of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 35. The test statistic of the completely randomized ANOVA design equals: a. sum of squares for treatments / sum of squares for error b. sum of squares for error / sum of squares for treatments c. mean square for treatments / mean square for error d. mean square for error / mean square for treatments e. sum of squares for error / mean square for error ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 36. In one-way ANOVA, suppose that there are three treatments with

region for this test at the 5% level of significance is: a. F > 3.24 b. F > 4.08 c. F > 3.63 d. F > 3.81 e. F > 3.22 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice

and

. Then the rejection

Chapter 11 - The Analysis of Variance HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/4/2019 9:41 AM 37. In one-way ANOVA test, the test statistic is F = 4.25. The rejection region is F > 3.06 for the 5% level of

significance, F > 3.8 for the 2.5% level, and F > 4.89 for the 1% level. For this test, the approximate p-value is: a. greater than 0.05 b. between 0.025 and 0.05 c. between 0.01 and 0.025 d. approximately 0.05 e. approximately 0.01 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 38. Which of the following is not a required condition for one-way ANOVA? a. The populations are normally distributed. b. The sample sizes must be equal. c. The population variances are equal. d. The samples are selected randomly and independently from their respective populations. e. None of these. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 39. The distribution of the test statistic for analysis of variance is the: a. normal distribution b. Student t-distribution c. F-distribution d. binomial distribution e. chi-square distribution ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM

Chapter 11 - The Analysis of Variance 40. Which of the following is not true for the F-distribution? a. It is symmetric around zero. b. It is skewed to the right. c. Its values are always positive. d. It is used in ANOVA test. e. All of these. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/4/2019 9:49 AM 41. In the completely randomized design of ANOVA where there are k treatments and n observations, the

degrees of freedom for the F-statistic are equal to: a. b. c. d. e. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/4/2019 9:57 AM 42. The degrees of freedom for a denominator in a one-way ANOVA test including 3 population means with 10

observations sampled from each population is equal to: a. 30 b. 27 c. 13 d. 12 e. 9 ANSWER:

POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM

Chapter 11 - The Analysis of Variance 43. In a completely randomized design for ANOVA, the number of degrees of freedom for the numerator and

denominator are 3 and 16, respectively. The total number of observations must equal: a. 20 b. 48 c. 32 d. 19 e. 24 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 44. An experimental plan that creates one treatment group for each treatment and then randomly assigns each

experimental unit to one of these groups is called: a. a completely randomized design b. a randomized block design c. either a completely randomized design or a randomized block design d. a matched-pairs design e. none of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 45. The analysis of variance helps us compare the means of two or more quantitative populations. Thus, it might

be used by the manager of a farm who wants to know whether there is any difference in: a. the average crop yield associated with the use of five types of fertilizer b. the average crop yield associated with five alternative quantities of a given type of fertilizer that

might be applied c. the average crop yield associated with five alternative times at which a given quantity of a given type of fertilizer might be applied d. all of these e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/4/2019 9:58 AM

Chapter 11 - The Analysis of Variance 46. Which of the following statements about ANOVA completely randomized design is correct? a. The ANOVA test assumes that the sampled populations are normally distributed. b. The ANOVA test assumes that the sampled populations have a common variances

. c. The ANOVA test assumes that the samples are randomly and independently selected from their respective populations. d. All of these. e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 47. Which of the following statements about the ANOVA table is correct? a. It is a summary table that shows, for each source of variation, the sum of squares, the degrees of

freedom, and the ratio of the sum of squares to the associated degrees of freedom (called the mean square). b. It shows the F statistic. c. It shows the statistics used to test hypotheses about the population means. d. Both “It is a summary table that shows, for each source of variation, the sum of squares, the degrees of freedom, and the ratio of the sum of squares to the associated degrees of freedom (called the mean square)” and “It shows the F statistic”. e. Neither “It is a summary table that shows, for each source of variation, the sum of squares, the degrees of freedom, and the ratio of the sum of squares to the associated degrees of freedom (called the mean square)” nor “It shows the F statistic”. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/4/2019 10:00 AM 48. Which of the following correctly describes the treatment sum of squares in one-way ANOVA? a. It equals the sum of the squared deviations between each treatment sample mean and the grand mean,

multiplied by the number of observations made for each treatment. b. It equals the sum of the square deviations between each block sample mean and the grand mean, multiplied by the number of observations made for each block, multiplied by the number of observations per cell. c. It equals the number of rows (or columns) multiplied by the sum of the squared deviations of the column-block sample means from the grand mean. d. It equals the number of columns (or rows) multiplied by the sum of the squared deviations of the

Chapter 11 - The Analysis of Variance

row-block sample means from the grand mean. e. None of these. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 49. Which of the following correctly describes the F statistic for the completely randomized design? a. It equals the ratio of mean squares for treatments (MST) to mean squares for error (MSE). b. It equals the ratio of sum of squares for treatments (SST) to sum squares for error (SSE). c. It equals the ratio of sum of squares for error (SSE) to total sum of squares (Total SS). d. All of these. e. None of these. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/4/2019 10:03 AM 50. In one-way ANOVA, the sum of the squared deviations of each individual sample observation (regardless of

the sample to which it belongs) from the mean of all observations is called: a. the F statistic b. the total sum of squares c. the grand mean d. the unexplained variance e. the F statistic and the total sum of squares ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 51. In any ANOVA test, whenever the computed F statistic: a. falls short of a chosen critical value of F, the null hypothesis of equal population means should be

rejected b. falls short of a chosen critical value of F, the alternative hypothesis of unequal population means should be accepted c. exceeds a chosen critical value of F, the null hypothesis of equal population means should be rejected

Chapter 11 - The Analysis of Variance d. exceeds a chosen critical value of F, the null hypothesis of equal population means should be

accepted e. falls short of a chosen critical value of F, the alternative hypothesis of equal population means should be rejected ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 52. All members of the F-distribution family are: a. skewed right between values of and b. skewed right between values of 0 and c. skewed left between values of

and 0 d. skewed left between values of 0 and e. correctly described by “skewed right between values of 0 and ” and “skewed left between values of and 0”, which is why the normal distribution is a special case of the F-distribution family ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/4/2019 10:07 AM 53. In a one-way ANOVA, if the null hypothesis is a. at least one of the means are different from the others b.

at least two of the means are different from the others

at least three of the means are different from the others

all populations means differ

none of the populations means differ

then the alternative hypothesis is:

ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 54. In a one-way ANOVA, if

and a sample of size 25 is selected at random from each of the five populations, then which of the following is the correct critical value at ? a. z = 1.645 b. t = 2.1318

Chapter 11 - The Analysis of Variance c. F = 2.87 d.

= 9.488 e. z = 2.164 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 55. Which of the following statements is true in a one-way ANOVA? a. The critical value of the test will be a value obtained from the F-distribution. b. If the null hypothesis is rejected, it may still be possible that two or more of the population means

equal. c. The degrees of freedom associated with the sum of squares for treatments is equal to one less than the number of populations. d. All of these. e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 56. In a one-way ANOVA, which of the following statements is true? a. The sample sizes must be equal. b. The mean squares for treatments (MST) will be larger than the mean squares for error (MSE) if the

null hypothesis is rejected. c. The population means are all equal. d. All of these. e. None of these. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 57. Which of the following statements is false? a. The sum of squares for treatments (SST) explains some of the variation. b. The sum of squares for error (SSE) measures the amount of variation that is unexplained. c. The total sum of squares Total SS = SST + SSE.

Chapter 11 - The Analysis of Variance d. The total sum of squares Total SS measures the amount of variation within the samples. e. The sum of squares for treatments (SST) explains some of the variation and the total sum of squares

Total SS = SST + SSE. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 58. In one-way ANOVA, the pooled variation within the k samples is measured by: a. the sum of squares for treatments b. the sum of squares for error c. the total sum of squares d. the degrees of freedom e. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/4/2019 3:21 PM 59. In one-way ANOVA, the total sum of squares equals a. sum of squares for treatments plus sum of squares for error b. sum of squares for error minus sum of squares for treatments c. sum of squares for error plus mean square for error d. mean square for treatments plus mean square for error e. mean square for error minus mean square for treatments ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/4/2019 3:36 PM 60. In one-way ANOVA, suppose that there are four treatments with

rejection region for this test at the 5% level of significance is: a. b. c.

, and

. Then the

Chapter 11 - The Analysis of Variance d. e. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/4/2019 3:56 PM 61. In an ANOVA test, the test statistic is F = 6.75. The rejection region is F > 3.97 for the 5% level of

significance, F > 5.29 for the 2.5% level, and F > 7.46 for the 1% level. For this test, the p-value is: a. greater than 0.05 b. between 0.025 and 0.05 c. between 0.01 and 0.025 d. approximately 0.05 e. less than 0.01 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 62. Which of the following is not a required condition for one-way ANOVA? a. The sample sizes must be equal. b. The populations must all be normally distributed. c. The population variances must be equal.. d. The samples for each treatment must be selected randomly and independently. e. None of these. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 63. The analysis of variance is a procedure that allows statisticians to compare two or more population: a. means b. proportions c. variances d. standard deviations e. none of these ANSWER: a

Chapter 11 - The Analysis of Variance POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 64. The distribution of the test statistic for analysis of variance is: a. skewed right and has

degrees of freedom b. skewed left and has degrees of freedom c. symmetric about 0 and has degrees of freedom d. symmetric about the population mean and has degrees of freedom e. none of these ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/5/2019 4:05 AM 65. Consider the following ANOVA table:

Source of Variation Treatments Error Total

SS 4 30 34

df 2 12 14

MS 2.0 2.5

F 0.80

The number of treatments is: a. 13 b. 5 c. 3 d. 12 e. 6 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 66. One-way ANOVA is applied to three independent samples having means 10, 13, and 18, respectively. If

each observation in the third sample were increased by 30, the value of the F-statistics would: a. increase b. decrease

Chapter 11 - The Analysis of Variance c. remain unchanged d. increase by 30 e. increase by 60 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 67. In a completely randomized design for ANOVA, the numerator and denominator degrees of freedom are 4

and 25, respectively. The total number of observations must equal: a. 24 b. 25 c. 29 d. 30 e. 31 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 68. The number of degrees of freedom for the denominator in one-way ANOVA test involving 4 population

means with 15 observations sampled from each population is: a. 60 b. 19 c. 56 d. 45 e. 34 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 69. Consider the following partial ANOVA table:

Source of Variation Treatments Error Total

SS 75 60 135

df * * 19

MS 25 3.75

F 6.67

Chapter 11 - The Analysis of Variance

The numerator and denominator degrees of freedom (identified by asterisks) are: a. 4 and 15 b. 3 and 16 c. 15 and 4 d. 16 and 3 e. 6 and 16 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 70. For which of the following departures from the conditions required for a completely randomized design is

the procedure not considered robust? a. The populations are not normally distributed. b. The population variances are not equal. c. The samples are not independent. d. All of these. e. None of these. ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/5/2019 4:11 AM 71. One-way ANOVA is performed on three independent samples with

, , and value obtained from the F-table for this test at the 2.5% level of significance equals: a. 3.55 b. 39.45 c. 4.56 d. 29.45 e. 3.46

. The critical

ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 72. A professor of statistics in Michigan State University wants to determine whether the average starting

Chapter 11 - The Analysis of Variance

salaries among graduates of the 15 universities in Michigan are equal. A sample of 25 recent graduates from each university was randomly taken. The appropriate degrees of freedom for the ANOVA test are equal to: a.

and

ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/5/2019 4:19 AM 73. A mechanical engineer at a manufacturing plant keeps a close watch on the performance and condition of

the machines. The following data are the weight losses (in milligrams) of certain machine parts due to friction when used with three different lubricants.

Total Means Standard Deviations

Lubricant A 12 9 8 11 10 8 7 6 71 8.875 2.031

Lubricant B

Lubricant C

10 8 9 13 8 7 5 11 71 8.875 2.475

12 8 14 11 12 13 7 8 85 10.625 2.615

How many degrees of freedom are associated with the F test statistic?

Calculate the value of the test statistic F. Round your answer to four decimal places. F=

Chapter 11 - The Analysis of Variance

Set up the rejection region for = 0.01. Round your answer to two decimal places. The rejection region is F>

What is the appropriate conclusion?

One lubricants.

conclude that there is a significant difference in average weight loss among the three

ANSWER:

; 1.4336; 5.78; Fail to reject the null hypothesis; cannot

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/5/2019 5:49 AM 74. A consumer would like to know if there is a difference in the performance of three different laundry

detergents. Eighteen pieces of white cloth were soiled with grape juice then washed in one of the three detergents A, B, or C. The resulting whiteness readings are listed below, where the larger number indicates whiter fabric. DETERGENT A 77 71 81 78 76 80

DETERGENT B 73 68 66 74 70 60

DETERGENT C 84 78 82 81 78 80

(Round your answers to three decimal places if necessary.) How many degrees of freedom are associated with the F test statistic?

Calculate the value of the test statistic F. F= Set up the rejection region for = 0.05. The rejection region is F > What is the appropriate conclusion?

Chapter 11 - The Analysis of Variance

The sample evidence detergents.

that the true mean whiteness readings are not the same for the three

Develop a 95% confidence interval for CI =

Enter (n1, n2)

Develop a 95% confidence interval for CI =

Enter (n1, n2)

ANSWER:

; 15.567; 3.682; Reject the null hypothesis; supports; (73.821, 80.513); (-16.731, -7.269)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/8/2019 8:56 AM 75. A textile company is interested in knowing if there is a difference in the breaking strength of four different

kinds of thread.

Total Means Standard Deviations

Thread 1 17.8 15.2 16.5 16.3 18.5 84.3 16.86 1.301

Thread 2

Thread 3

21.2 18.7 18.6 20.6 17.9 97.0 19.40 1.420

16.4 18.0 16.7 19.5 16.8 87.4 17.48 1.283

Thread 4 19.2 18.0 17.9 18.1 20.3 93.5 18.70 1.037

Test whether there is a significant difference in the mean breaking strength of the four kinds of thread. Calculate the test statistic. Round your answer to three decimal places. F= Set up the rejection region for = 0.05. Round your answer to two decimal places. The rejection region is F >

Chapter 11 - The Analysis of Variance

What conclusion can be drawn?

of the mean breaking strengths of the four kinds of threads is significantly different from the others. Find the approximate p-value. Do not round the limits of the interval. p-value is in the interval

Enter (n1, n2)

Find a 90% confidence interval for

. Round the limits to two decimal places.

CI =

Enter (n1, n2)

ANSWER:

4.118; 3.24; Reject the null hypothesis; At least one; (0.010, 0.025); (-2.02, 0.78)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/9/2019 2:40 AM 76. Based on public demand, price for seeds, and average yield, a farmer must choose which variety of wheat to

grow. In the first step toward making a decision, the farmer planted eight test plots each with three varieties of wheat. The recorded yields (in pounds per plot) were used in an analysis of variance. Source Model Error Total

DF 2 21 23

SS 134.3333 49.0000 183.3333

MS 67.1667 2.3333

F 28.79

Use the output from the analysis of variance to test the null hypothesis of no difference among the mean yields of the three varieties of wheat. Use to draw conclusions. (Round your answers to two decimal places.) Test statistic F = The rejection region is F>

What is the appropriate conclusion?

The sample in this problem

that the mean yields for the three varieties are not the same.

Chapter 11 - The Analysis of Variance ANSWER:

28.79; 6.89; Reject the null hypothesis; suggests

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/5/2019 5:51 AM 77. Suppose a reading comprehension test is given to random samples of three seventh graders from each of five

different schools. The samples are chosen so that each school provides a student categorized as low IQ, average IQ, and high IQ. Perform an analysis using the data below treating the IQs as blocks. IQ Low Average High

A 45 67 95

B 65 90 75

C 85 90 95

D 30 70 99

E 47 50 52

Is there sufficient evidence to reject the null hypothesis of no difference between the true mean test scores of the five schools? Draw conclusions using = 0.05. (Round your answers to two decimal places.) What is the F-statistic?

Reject Region: Reject H0 if |F| > Can you reject the null hypothesis? Use = 0.05.

One five schools. ANSWER:

conclude that there is a significant difference between the true mean test scores of the 2.76; 3.84; Do not reject the null hypothesis; cannot

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/5/2019 7:33 AM 78. A travel agency primarily reserves flights with four major airlines. The agency would like to know if the

true mean price for the four airlines is the same. Below are the prices for flights leaving from the same city traveling to five different destinations.

Chapter 11 - The Analysis of Variance DESTINATION V W X Y Z

A 350 450 300 800 650

B 300 400 325 750 650

C 325 495 325 775 625

D 375 450 375 825 675

Perform an analysis of variance treating the destinations as blocks. (Round your answers to three decimal places.) What is the F-statistic?

Test the null hypothesis of no difference in the true mean price for the four airlines in a completely randomized design. Use = 0.05. Reject Region: Reject H0 if |F| > Can you reject the null hypothesis?

Why is it necessary to treat the destinations as blocks?

Develop and interpret a 90% confidence interval for decimal places.

ANSWER:

, (use the MSE value). Round the limits to three

Enter (n1, n2). 4.126; 3.490; Reject the null hypothesis; Because there is variability in the prices of flights to different destinations. Our goal was to see if the airlines had different prices, so it was important to block this variable.; (-26.949, 28.949)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/8/2019 9:39 AM 79. Due to his high blood pressure, Sam watches the sodium content of the foods that he eats. Five samples for

each of four brands of canned turkey (97% fat free) were tested for sodium content, measured in milligrams of sodium per 2-ounce serving. Brand 1

Brand 2

Brand 3

Brand 4

Chapter 11 - The Analysis of Variance 250 251 260 255 245

175 185 175 180 165

175 180 180 170 190

200 210 210 195 205

The following summary table and ANOVA were generated by statistical software as shown below: SUMMARY TABLE Groups Count Brand 1 5 Brand 2 5 Brand 3 5 Brand 4 5

Sum 1261 880 895 1020

Average 252.2 176 179 204

ANOVA TABLE Source of Variation Brand Error

df 3 16

SS 18632.4 736.8

Total

19369.2

MS 6210.8 46.05

Variance 31.7 55 55 42.5

F 134.871

P-value F crit 0.000 3.23887

Use the p-value approach to test whether there is a significant difference in mean amount of sodium in the four brands. Let = 0.05. Can you reject the null hypothesis?

of the brands of canned turkey has a significantly different mean sodium content from the others. ANSWER:

Reject the null hypothesis; At least one

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/5/2019 8:03 AM 80. The following statistics were calculated based on samples drawn from three normal populations: Statistic n s

1 10 95 10

2 10 86 12

3 10 92 15

Set up the ANOVA table and test at the 5% level of significance to determine whether differences exist among the population means.

Chapter 11 - The Analysis of Variance

(Round your answers to three decimal places.) Test statistic = Critical Value(s) = Conclusion: Interpretation: Differences

exist among the population means.

ANSWER:

1.343; 3.354; Do not reject H0; do not

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/10/2019 4:06 AM 81. Water samples were taken at four different locations in a river to determine whether the quantity of

dissolved oxygen, a measure of water pollution, varied from one location to another. Locations 1 and 2 were selected above an industrial plant, one near the shore and the other in midstream; location 3 was adjacent to the industrial water discharge for the plant; location 4 was slightly downriver in midstream. Five water specimens were randomly selected at each location, but one specimen, corresponding to location 4, was lost in the laboratory. The data and an ANOVA computer printout are provided here (the greater the pollution, the lower the dissolved oxygen readings). Location Mean Dissolved Oxygen Content 1 5.9 6.1 6.3 6.1 6.0 2 6.3 6.6 6.4 6.4 6.5 3 4.8 4.3 5.0 4.7 5.1 4 6.0 6.2 6.1 5.8 SUMMARY TABLE Groups Count Location 1 5 Location 2 5 Location 3 5 Location 4 4

Sum 30.4 32.2 23.9 24.1

ANOVA TABLE Source of Variation Location Error

SS 7.8361 0.6155

df 3 15

Average 6.08 6.44 4.78 6.025 MS 2.6120 0.0410

Variance 0.022 0.013 0.097 0.0292 F 63.6562

P-value 0

F crit 3.2874

Chapter 11 - The Analysis of Variance 18

Total

8.4516

Do the data provide sufficient evidence to indicate a difference in the mean dissolved oxygen contents for the four locations? Conclusion: There

a significant difference in the mean dissolved oxygen content for the four locations.

Compare the mean dissolved oxygen content in midstream above the plant with the mean content adjacent to the plant (location 2 versus location 3). What is the 95% confidence interval (CI) for ? Round the limits to three decimal places. CI =

Enter (n1, n2)

ANSWER:

Reject H0; is; (1.387, 1.933)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/8/2019 8:35 AM 82. Physicians depend on laboratory test results when managing medical problems such as diabetes or epilepsy.

In a uniformity test for glucose tolerance, three different laboratories were each sent nt = 5 identical blood samples from a person who had drunk 50 milligrams (mg) of glucose dissolved in water. The laboratory results (in mg/dl) are listed here: Lab 1 121.3 111.9 110.1 105.4 101.6

Lab 2 99.5 113.2 108.9 109.1 100.4

Lab 3 104.2 109.7 102.3 111.2 106.6

(Round your answers to three decimal places.) Do the data indicate a difference in the average readings for the three laboratories? Use Tukey's method for paired comparisons to rank the three treatment means. Use = 0.05. What is the F-statistic?

What is the p-value?

Chapter 11 - The Analysis of Variance

Can you reject the null hypothesis?

There

sufficient evidence to indicate a difference in the treatment means.

Give the value of ω that you would use to make pairwise comparisons of the treatment means for α = 0.05. ω= Rank the treatment means using pairwise comparisons. Enter just the subscripts in order (1, 3, etc.).

ANSWER:

0.611; 0.559; Fail to reject the null hypothesis; is not; 9.987; 3, 2, 1

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/9/2019 3:44 AM 83. An insurance company is considering opening a new branch in Lansing. The company will choose the final

location from two locations within the city. One of the factors in the decision is the annual family income (in thousands of dollars) of five families randomly sampled from a radius of five miles from the potential locations. Area 1 73 48 46 53 51

Area 2 74 50 81 49 61

Perform equal-variances t-test at the 5% significance level to determine whether the population means differ. (Round your answers to three decimal places.) What is the t-statistic?

Reject Region: Reject H0 if |t| > Conclusion:

Chapter 11 - The Analysis of Variance

The population means

differ.

Perform an F-test for one-way ANOVA at the 5% level of significance to determine whether the population means differ. (Round your answers to three decimal places.) What is the F-statistic?

Reject Region: Reject H0 if |F| > Conclusion: The population means

differ.

What is the relation between the observed t and observed F test statistics from the previous two questions? F Does the same relation hold true for the corresponding critical values?

If we want to determine whether the population mean income for area 2 is higher than that for area 1, can we still use both the t and F-tests applied in the previous questions?

Explain.

ANSWER:

-1.098; 2.306; Do not reject H0; do not; 1.205; 5.318; Do not reject H0; do not; tsquared; Yes; No; We must use the equal variances t-test. We cannot use the analysis of variance F-test since this technique only allows us to test for a difference.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/8/2019 7:16 AM 84. Tukey’s method for paired comparisons determines a critical number,

means has a difference greater than

, such that if any pair of sample , we conclude that the pair's two corresponding population means are

Chapter 11 - The Analysis of Variance

different. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/9/2019 3:51 AM 85. Tukey’s method for paired comparisons determines a critical number

, such that, if any pair of sample means has a difference smaller than this critical number, we conclude that the pair's two corresponding population means are different. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/9/2019 3:53 AM 86. The studentized range is the difference between the smallest and the largest in a set of k samples means. It is

used for determining whether there is a difference in a pair of population means. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 87. Tukey's method for making paired comparisons is based on the usual ANOVA assumptions. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 88. Tukey's method for paired comparisons makes the probability of declaring that a difference exists between

at least one pair in a set of k treatments, when no difference exists, equal to 1 - .

Chapter 11 - The Analysis of Variance a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 89. Tukey's method for paired comparisons assumes that the sample means are equal and independent of each

other. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 90. Which of the following correctly describes Tukey's method of paired comparisons? a. It is a statistical technique designed to test whether the means of more than two quantitative

populations are equal. b. It is a method employed as a follow-up to ANOVA that seeks out "honestly significant differences" between paired sample means. c. It is a method to determine whether different statistical populations having equal variances. d. It is a method to measure a statistical test's sensitivity to any breach of ANOVA basic assumptions. e. None of these. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 91. Which of the following is not true for Tukey’s method for paired comparisons? a. It is based on the studentized range statistic q to obtain the critical value needed to construct

individual confidence intervals. b. It requires that all sample sizes are equal, or at least similar. c. It can be employed instead of the analysis of variance. d. All of these. e. None of these. ANSWER:

Chapter 11 - The Analysis of Variance POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/9/2019 3:54 AM 92. Why would you use Tukey’s method for paired comparisons? a. To test for normality. b. To test for homogeneity of variance. c. To test independence of errors. d. To test for differences in pairwise means. e. To test for differences in sample population means. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/9/2019 3:55 AM 93. Tukey’s method for paired comparisons is used in one-way ANOVA and if we conclude that there is no

difference between the treatment means, the null hypothesis is: a. rejected b. accepted c. not rejected d. either rejected or accepted e. neither rejected nor accepted ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/9/2019 4:01 AM 94. Independent random sampling design was used to compare the means of six treatments based on samples of

four observations per treatment. The pooled estimator of

is 9.42, and the sample means follow:

Give the value of that you would use to make pairwise comparisons of the treatment means for = 0.05. Round your answer to two decimal places if necessary. ω=

Chapter 11 - The Analysis of Variance

Rank the treatment means using pairwise comparisons. Enter just the subscripts in order (1, 4, etc.).

ANSWER:

6.89; 4; 2; 1; 5; 3; 6

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/9/2019 4:04 AM 95. The data that follow are observations collected from an experiment that compared four treatments, A, B, C,

and D, within each of three blocks, using a randomized block design. Block 1 2 3

A 7 5 13

B 11 10 16

C 9 6 15

D 10 8 15

Rank the four treatment means using Tukey's method of paired comparisons with = 0.01. Ranked means (

is the smallest,

is the largest). Round the answers to two decimal places if necessary.

= = = = ANSWER:

8.33; 10; 11; 12.33

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/9/2019 4:33 AM 96. A building contractor employs three construction engineers, A, B, and C to estimate and bid on jobs. To

determine whether one tends to be a more conservative (or liberal) estimator than the others, the contractor selects four projected construction jobs and has each estimator independently estimate the cost (in dollars per square foot) of each job. The data are shown in the table:

Chapter 11 - The Analysis of Variance Estimator A B C

1 35.10 37.45 36.30

2 34.50 34.60 35.10

3 29.25 33.10 32.45

4 31.60 34.40 32.90

Analyze the experiment using the appropriate methods. Use the level of significance = 0.05. Round the value of ω to three decimal places. Means Plot

= There

differences between the means μA and μB.

ANSWER:

;

1.885; are POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/10/2019 4:55 AM 97. A randomized block design should not be used when treatments and blocks both correspond to experimental

factors of interest to the researcher. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False

Chapter 11 - The Analysis of Variance DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 98. In a two-way ANOVA, there are 4 levels for factor A, 3 levels for factor B, and 3 observations within each

of the 12 factor combinations. The number of treatments in this experiment will be 36. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 99. The randomized block design is a two-way classification design. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 100. A randomized block experiment having five treatments and four blocks produced the following values:

Total SS = 1500, SST = 275, SSE = 153. The value of MSB must be 268. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 101. In a two-way ANOVA, there are 4 levels for factor A, 3 levels for factor B, and two observations within

each of the 12 factor combinations. The number of treatments in this experiment will be 12. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM

Chapter 11 - The Analysis of Variance DATE MODIFIED: 2/4/2019 9:36 AM 102. Blocking is a procedure that lets extraneous factors operate during an experiment but assures - by virtue of

the random selection of experimental units and their subsequent random assignment to experimental and control groups - that each treatment has an equal chance to be enhanced or handicapped by these factors. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 103. In employing the randomized block design, the primary interest lies in reducing sum of squares for blocks

(SSB). a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 104. The completely randomized design is an experimental plan that divides all available experimental units into

blocks of fairly homogeneous units - each block containing as many units as there are treatments or some multiple of that number - and then randomly matches each treatment with one or more units within each block. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 105. In the analysis of variance, the sum of the squared deviations between each block sample mean and the

grand mean, multiplied by the number of observations made for each block, multiplied by the number of observations per cell (which may well equal 1) equals the blocks mean square. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False

Chapter 11 - The Analysis of Variance HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 106. Two samples of ten each from the male and female workers of a large company have been taken. The data

involved the wage rate of each worker. To test whether there is any difference in the average wage rate between male and female workers a pooled-variances t-test will be considered. Another test option to consider is ANOVA. The most likely ANOVA to fit this test situation is the randomized block design. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 107. Three tennis players, a beginner, an experienced, and a professional, have been randomly selected from the

membership of a large city tennis club. Using the same ball, each person hits four serves with each of five racquet models, with the five racquet models selected randomly. Each serve is clocked with a radar gun and the result recorded. Among ANOVA models, this setup is most like the one-way ANOVA. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/9/2019 7:01 AM 108. When the problem objective is to compare more than two populations using two factors that affect the

response, the experimental design that is the counterpart of the matched pairs experiment is called the randomized block design. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/9/2019 4:58 AM 109. A randomized block design ANOVA has two treatments. The test to be performed in this procedure is

equivalent to dependent samples t-test. a. True

Chapter 11 - The Analysis of Variance b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 110. A randomized block design ANOVA has five treatments and four blocks. The computed test statistic (value

of F) is 6.25. With a 0.05 significance level, the conclusion will be to accept the null hypothesis. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 111. The randomized block design is also called the two-way analysis of variance. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 112. The F-test of the randomized block design of the analysis of variance has the same requirements as the

independent samples design; that is, the random variable must be normally distributed and the population variances must be equal. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 113. The purpose of designing a randomized block experiment is to reduce the variation among the treatment

means (SST) to more easily detect differences between the treatment means. a. True b. False

Chapter 11 - The Analysis of Variance ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/9/2019 5:02 AM 114. If we first arrange test units into similar groups before assigning treatments to them, the test design we

should use is the randomized block design. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 115. The randomized block design with two treatments is equivalent to a large-sample z-test. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/9/2019 6:29 AM 116. A randomized block design with 4 treatments and 5 blocks produced the following sum of squares values:

SS(Total) = 2000, SST = 400, SSE = 200. The value of MSB must be 350. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 117. The equation: "Total SS = SST + SSB + SSE" applies to which ANOVA model? a. one-way ANOVA b. a two-factor factorial design c. completely randomized design d. randomized block design

Chapter 11 - The Analysis of Variance e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 118. In the randomized block design for ANOVA where k is the number of treatments and b in the number of

blocks, the degrees of freedom for error is given by: a. bk 1 b. kb + 1 c. (b 1)(k 1) d. k + b 1 e. (b + 1)(k + 1) ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 119. An analysis of variance that controls extraneous factors by using the randomized block design is called: a. one-way ANOVA b. two-way ANOVA c. three-way ANOVA d. four-way ANOVA e. five-way ANOVA ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 120. Which of the following statements about blocks variation is false? a. It equals the sum of the squared deviations between each block sample mean and the grand mean. b. It measures the variation among block sample means, which is attributable not to chance to inherent

differences among blocks of experimental units. c. In two-way ANOVA, it equals the blocks mean square. d. In three-way ANOVA, it equals the blocks sample mean. e. None of these. ANSWER:

Chapter 11 - The Analysis of Variance POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 121. In a randomized block design of ANOVA, how many factors are there to be analyzed? a. one factor b. two factors c. three factors d. four or more factors e. all of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 122. In a randomized block design of ANOVA, which of the following statements is true? a. The sum of squares for treatments (SST) measures the variation among the treatment means. b. The sum of squares for blocks (SSB) measures the variation among the block means. c. The sum of squares for error (SSE) measures the variation of the differences among the treatment

observations within blocks. d. All of these. e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 123. In a randomized block design of ANOVA, which of the following correctly describes the number of

degrees of freedom associated with the sum of squares for treatments? a. One less than the total number in observations in all samples. b. One less than the number of blocks. c. One less than the number of populations involved. d. One more than the number of populations involved. e. None of these. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice

Chapter 11 - The Analysis of Variance HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 124. The F-test of the randomized block design of the analysis of variance requires that: a. the random variable of interest must be normally distributed b. the population variances must be equal c. the population means must be equal d. the random variable of interest must be normally distributed and the population variances must be

equal. e. the random variable of interest must be normally distributed and the population means must be equal. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/9/2019 6:42 AM 125. In the randomized block design for ANOVA, where k is the number of treatments and b in the number of

blocks, the number of degrees of freedom for treatments is: a. k 1 b. b 1 c. (k 1)(b 1) d. kb 1 e. kb + 1 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/9/2019 6:46 AM 126. In the randomized block design for ANOVA, SS(Total) equals: a. SST + SSE b. SST − SSB + SSE c. SST − SSB − SSE d. SST + SSB + SSE e. SST + SSB − SSE ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice

Chapter 11 - The Analysis of Variance HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/9/2019 6:54 AM 127. Three tennis players, a beginner, an intermediate, and advanced, have been randomly selected from the

membership of a racquet facility club in a large city. Using the same tennis ball, each player hits ten serves, one with each of three racquet models, with the three racquet models selected randomly. The speed of each serve is measured with a machine and the result recorded. Among the ANOVA models listed below, the most likely model to fit this situation is the: a. one-way ANOVA b. two-way ANOVA c. randomized block design d. matched-pairs model e. chi-square test ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 128. The primary interest in designing a randomized block experiment is to: a. reduce the variation among blocks b. increase the variation among treatment means to more easily detect differences among the treatment

means c. reduce the variation among treatment means to more easily detect differences among the treatment means d. increase the total sum of squares e. none of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/9/2019 7:04 AM 129. The randomized block design with exactly two treatments is equivalent to a two-tail: a. independent samples z-test b. independent samples equal-variances t-test c. independent samples unequal-variances t-test d. matched pairs t-test e. independent samples t-test ANSWER:

Chapter 11 - The Analysis of Variance POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 130. In the randomized block design ANOVA, the sum of squares for error equals: a. Total SS SST b. Total SS SSB c. Total SS SST SSB d. Total SS SS(A) e. Total SS SS(A) SS(B) SS(AB) ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 131. A randomized block design with 4 treatments and 5 blocks produced the following sum of squares values:

Total SS = 1951, SST = 349, SSE = 188. The value of SSB must be: a. 1414 b. 537 c. 1763 d. 1602 e. 1312 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 132. A consumer was interested in determining whether there is a significant difference in the price charged for

tools by three hardware stores. The consumer selected five tools and recorded the price for each tool in each store. The following data was recorded: Store Store 1 Store 2 Store 3

1 $32.00 $30.00 $29.50

2 $3.95 $2.95 $3.50

3 $1.50 $1.50 $1.75

(Round your answers to four decimal places.)

Ftool =

4 $2.95 $2.45 $2.45

5 $4.00 $5.00 $4.50

Chapter 11 - The Analysis of Variance

p-value = Fstore = p-value = Conclusion: ANSWER:

958.4799; 0; 0.9518; 0.4258; Only the tool is significant.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/9/2019 7:21 AM 133. An avid runner was interested in whether there is a significant difference in the average wear (measured in

weeks of use) among three brands of running shoes. To answer the question, the runner randomly selected six runners and assigned them to wear each of the three brands of running shoes until the shoes wore out. Each of the runners wore the brands of shoes in a random order. After the data had been recorded, the following output was generated using Minitab:

What are the blocks?

What are the treatments?

The p-value

indicate significant results.

Is blocking necessary in this problem?

Chapter 11 - The Analysis of Variance

Justify your answer.

Use the p-value approach to determine whether there is a significant difference in the average wear between the three brands of running shoes. Let = 0.05.

The p-value

ANSWER:

indicate significant results.

of the brands of running shoes has a significantly different average wear than the others. Runners; Brands; does; Yes; Since there is a significant difference in the means of the runners, blocking is necessary.; does; At least one

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 134. A company conducted an experiment to determine the effect of two types of incentive pay plans on worker

productivity for workers of two shifts. The company used an equal number of production workers from each of the two shifts and one-half of these workers were assigned to each plan. Then five workers from each pay planshift combination were selected and their productivity (in number of items produced) recorded for a one week period. The following output was generated using Minitab:

Is there significant interaction present in this problem? Let = 0.05.

The p-value

indicate significant interaction.

Based on the previous answer, is testing for the main effects, plan and shift, appropriate?

Chapter 11 - The Analysis of Variance

ANSWER:

does; Since significant interaction is present, the difference in plan means and shift means can be examined by looking at comparisons of the factor-level combinations (as opposed to comparing the factor means individually).

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 135. A study was conducted to compare automobile gasoline mileage for three brands of gasoline, A, B, and C.

Four automobiles, all of the same make and model, were used in the experiment, and each gasoline brand was tested in each automobile. Using each brand in the same automobile has the effect of eliminating (blocking out) automobile-to-automobile variability. The data (in miles per gallon) are as follows: Gasoline Brand A B C

1 16.9 18.4 17.3

2 18.2 19.3 18.7

3 18.5 19.1 18.0

4 17.3 18.9 19.0

Use Minitab or Excel to generate a summary table and the ANOVA table. Round your answers to two decimal places. Do the data provide sufficient evidence to indicate a difference in mean mileage per gallon for the three brands of gasoline? F= p-value = There brands of gasoline.

sufficient evidence to indicate a difference in mean mileage per gallon for the three

Is there evidence of a difference in mean mileage for the four automobiles? F= p-value = There automobiles.

sufficient evidence to indicate a difference in mean mileage per gallon for the four

ANSWER:

6.46; 0.03; is; 3.75; 0.08; is not

POINTS:

Chapter 11 - The Analysis of Variance QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/9/2019 7:42 AM 136. In ANOVA for an a b factorial experiment, it is necessary to have at least two measurements at each level of each factor in order to analyze any interaction between the factors. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 137. The number of cells in a two-way factor ANOVA is equal to a + b 1; where a is the number of levels of

factor A and b is the number of levels of factor B. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 138. In order to conduct a two-way factor ANOVA with replications, the number of replications r must be the

same in each cell. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 139. In a two-way factor ANOVA, the smallest number of replications required in any cell is 2, but all cells

must have the same number of replications. a. True b. False ANSWER: POINTS:

True 1

Chapter 11 - The Analysis of Variance QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 140. In a two-way factor ANOVA, the total sum of squares can be partitioned into four parts: the variation due

to factor A, the variation due to factor B, the error variation, and the variation due to blocking. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 141. In a two-way factor ANOVA, the variances of the populations are assumed to be equal unless the error

variation is zero. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 142. In a two-way factor ANOVA, if factors A and B do not interact, then neither A nor B can be considered

statistically significant. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 143. In a two-way factor ANOVA with replications, the null hypothesis for testing whether interaction exists is

that no interaction exists, while the alternative hypothesis is that interaction does exist. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False

Chapter 11 - The Analysis of Variance HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 144. In a two-way factor ANOVA with replications in which all hypotheses are to be tested at the .05

significance level, if the p-value for interaction is .0257, then we should conclude that no interaction exists between the levels of the two factors. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 145. In a two-way factor ANOVA with replications, the reason for separating out the sum of squares due to

interaction between factors A and B is to increase the chance of detecting significant differences across levels of factor A and factor B. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 146. In a two-way ANOVA, it is easier to interpret main effects when the interaction component is not

significant. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 147. A study will be undertaken to examine the effect of two kinds of background music and of two assembly

methods on the output of workers at a fitness shoe factory. Two workers will be randomly assigned to each of four groups, for a total of eight in the study. Each worker will be given a headphone set so that the music type can be controlled. The number of shoes completed by each worker will be recorded. The study considers whether the kind of music or the assembly method or a combination of music and method affect output. The ANOVA model most likely to fit this situation is the factorial experiment.

Chapter 11 - The Analysis of Variance a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/9/2019 8:00 AM 148. In a two-way factor ANOVA, the sum of squares due to both factors, the interaction sum of squares, and

the error sum of squares must add up to the total sum of squares. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 149. To which ANOVA model does the equation "Total SS = SSA + SSB + SS(AB) + SSE" apply? a. one-way ANOVA b. a two-factor factorial design c. completely randomized design d. randomized block design e. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/9/2019 8:03 AM 150. In the

factorial experiment, where a is the number of levels for factor A, b is the number of levels for factor B, and r in the number of replications of each of the ab factor combinations, the degrees of freedom for interaction is given by: a. (a 1)(b 1) b. (a 1)(r 1) c. (b 1)(r 1) d. ab(r 1) e. (b + 1)(r + 1) ANSWER: POINTS:

a 1

Chapter 11 - The Analysis of Variance QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 151. In a two-way ANOVA with replications, the test statistic for the interaction test is: a. b. c. d. e. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/10/2019 4:21 AM 152. In the two-way ANOVA where a is the number of factor A levels, b in the number of factor B levels, and r

in the number of replications, the number of degrees of freedom for error is: a. (a 1)(b 1) b. abr 1 c. (a 1)(r 1) d. ab(r 1) e. (a + 1)(r + 1) ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/10/2019 3:28 AM 153. When the effect of a level for one factor depends on which level of another factor is present, the most

appropriate ANOVA design to use in this situation is the: a. matched pairs design b.

factorial experiment

Chapter 11 - The Analysis of Variance c. completely randomized design d. randomized block design e. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/10/2019 3:36 AM 154. Interaction in an experimental design can be tested in: a. a completely randomized model b. a randomized block model c. a two-way factor model d. all ANOVA models e. none of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 155. In a two-way ANOVA, there are 4 levels for factor A, 5 levels for factor B, and 3 observations for each

combination of factor A and factor B levels. The number of treatments in this experiment equals: a. 60 b. 25 c. 20 d. 16 e. 12 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 2/4/2019 9:36 AM 156. In a two-way ANOVA, where a is the number of factor A levels, b is the number of factor B levels, and

n is the number of observations, the number of the degrees of freedom for the "error term" is: a. (a 1)(b 1) b. n ab c. (a 1) + (b 1)

Chapter 11 - The Analysis of Variance d. abn + 1 e. (a + 1)(b + 1) ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/10/2019 3:38 AM 157. A researcher at Michigan State University (MSU) wanted to determine whether different building signs

(building maps versus wall signage) affect the total amount of time visitors require to reach their destination and whether that time depends on whether the starting location is inside or outside the building. Three subjects were assigned to each of the combinations of signs and starting locations, and travel time in seconds from beginning to destination was recorded. A partial computer output of the appropriate analysis is given below:

The degrees of freedom for the different building signs are

The degrees of freedom for the different starting location are

The degrees of freedom for the interaction between the levels of signs and starting location are . The error degrees of freedom are

The mean squares value for starting location is The F test statistic for testing the main effect of types of signs is decimal places.)

. . (Round your answer to three

The F test statistic for testing the interaction effect between the types of signs and the starting location is . (Round your answer to four decimal places.) In order to determine the critical value of the F ratio against which to test for differences between the levels of factor A, we should use numerator df = , and denominator df = . In order to determine the critical value of the F ratio against which to test for differences between the levels of

Chapter 11 - The Analysis of Variance

factor B, we should use numerator df =

, and denominator df =

In order to determine the critical value of the F ratio against which to test for interaction between levels of Factor A and levels of Factor B, we should use numerator df = , and denominator df = . ANSWER: 1; 1; 1; 8; 12288; 3.174; 0.0109; 1; 8; 1; 8; 1; 8 POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:36 AM DATE MODIFIED: 4/10/2019 3:59 AM 158. A researcher is testing the effectiveness of a new cold medicine drug. The statistical research is conducted

to determine whether the new drug allows reducing the duration of the disease compared with the developed method of taking the medicine. Four groups of 20 people were randomly selected from patients of approximately the same age and social level for this experiment. The first group was taking a new medicine, the second group was taking an old proven medicine, the third group was taking a placebo, and the last group was not taking anything except vitamin C. Determine the degrees of freedom for this experiment.

df (treatments) =

df (error) =

df (total) = ANSWER:

3; 76; 79

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 4:43 AM DATE MODIFIED: 2/6/2019 4:49 AM

Chapter 12 - Simple Linear Regression and Correlation 1. In a simple linear regression problem, the following pairs of

are given: (6.75, 7.42), (8.96, 8.06), (10.30, 11.65), and (13.24, 12.15). Then, the sum of squares for error is: a. 39.2500 b. -0.0300 c. 4.2695 d. 39.2800 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:38 AM DATE MODIFIED: 4/24/2019 2:33 AM 2. A medical study investigated the link between obesity and television viewing habits in children. One part of

the study involved characterizing the difference in viewing habits between boys and girls. A regression model was used to compare the number of hours of television watched per week by boys with the number watched by girls. Use the computer printout below to determine whether there is a significant difference between these two groups. The variable named "Gender" in the printout is equal to one if the subject was a female, and zero if the subject was a male.

State your conclusion based on a 0.05 significance level. There ANSWER:

a significant difference in TV viewing habits between boys and girls. is

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:38 AM DATE MODIFIED: 4/11/2019 8:21 AM 3. In a simple linear regression setting, the deterministic model equation determines an exact value of the

Chapter 12 - Simple Linear Regression and Correlation

dependent variable y when the value of the independent variable x is given, since all points must lie exactly on the line. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 4. The sum of squares for regression (SSR) can never be larger than the sum of squares for error (SSE). a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 5. The value of the sum of squares for regression (SSR) can never be larger than 100. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 6. In a simple linear regression setting, the probabilistic model equation allows for some deviation of the points

about the regression line, making it a more practical model. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 7. The vertical spread of the data points about the regression line is measured by the y-intercept. a. True

Chapter 12 - Simple Linear Regression and Correlation b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 8. The method of least squares requires that the sum of the squared deviations between actual yvalues in the

scatter diagram and y-values predicted by the regression line be minimized. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/22/2019 7:13 AM 9. A regression analysis between sales (in $1000) and advertising (in $) resulted in the following least squares

line: = 60 + 5x. This implies that an increase of $1 in advertising is expected to result in an increase of $65 in sales. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 2:36 AM 10. A regression analysis between weight (y in pounds) and height (x in inches) resulted in the following least

squares line: = 135 + 6x. This implies that if the height is increased by 1 inch, the weight is expected to increase by an average of 6 pounds. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 2:38 AM

Chapter 12 - Simple Linear Regression and Correlation 11. In simple linear regression, if the estimated values

and the corresponding actual values

are equal, then

the standard error of estimate, SE( ), must equal -1. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 2:40 AM 12. The value of the sum of squares for error (SSE) can never be larger than the total sum of squares (Total SS). a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 13. If a least squares regression line has a y-intercept of 6.84 and a slope of 2.16, then when x = 1 the actual

value of y must be 9. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 14. Given that the sum of squares for error (SSE) is 52 and the sum of squares for regression (SSR) is 148, then

the coefficient of determination is 0.74. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 15. If the coefficient of determination is 0.982, then the slope of the regression line must be positive.

Chapter 12 - Simple Linear Regression and Correlation a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 16. A regression analysis between sales (in $1000) and advertising (in $100) resulted in the following least

squares line: = 77 +8x. This implies that if advertising is $600, then the predicted amount of sales (in dollars) is $125,000. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 2:41 AM 17. The residuals are observations of the error variable . Consequently, the minimized sum of squared

deviations is called the sum of squares for error, denoted SSE. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 18. One way to measure the strength of the relationship between the response variable y and the predictor

variable x is to calculate the coefficient of determination; that is, the proportion of the total variation in y that is explained by the linear regression of y on x. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM

Chapter 12 - Simple Linear Regression and Correlation 19. Regression analysis is a statistical method that seeks to establish an equation that allows the value of the

dependent variable to be estimated from the known value of one or more other variables. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/9/2019 1:36 AM 20. In regression analysis, the independent variable is a variable whose value is known and is being used to

explain or predict the value of another variable. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 21. In regression analysis, the dependent variable is a variable whose value is unknown and is being explained

or predicted with the help of another variable. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 22. A linear relationship is a relationship between any two variables, Y and X, such that many possible values

of Y can be associated with any one value of X. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/11/2019 4:08 AM 23. The linear equation determines an exact value of y when the value of x is given.

Chapter 12 - Simple Linear Regression and Correlation a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/11/2019 4:17 AM 24. A random error component is added to modify the deterministic model to explain the deviations of the

points about the line. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/11/2019 4:17 AM 25. The values of a and b found in the equation of the best-fitting line, y- intercept and slope parameters α and β, respectively.

, represent the estimates of the

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 2:45 AM 26. Some points that are below the prediction line, hence a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/23/2019 3:24 AM

, can be negative.

27. A measure of how well an estimated regression line fits the sample data on which it is based (denoted by

and equal to the proportion of the total variation in the values of the dependent variable, y, that can be explained

Chapter 12 - Simple Linear Regression and Correlation

by the association of y with x as measured by the estimated regression line) is called the sample coefficient of correlation. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 28. A dependent variable is the variable that we wish to predict in a regression model. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 29. In developing a scatterplot, you have the option of connecting the points or not. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 30. If two variables are related in a negative linear manner, the scatterplot will show points on the x, y space that

are generally moving from the upper left to the lower right. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 31. An automobile company in Michigan is interested in the relationship between the gender of their employees

and employee productivity. A good starting point in this analysis would be to compute the coefficient of determination and the correlation coefficient.

Chapter 12 - Simple Linear Regression and Correlation a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 32. In developing a simple linear regression model, only one independent variable is used to explain the

variation in a single dependent variable. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 33. In a sample linear regression model, the slope coefficient represents the average change in the independent

variable x for a one unit change in the dependent variable y. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 34. If a set of data contains no values of the independent variable x that are equal to zero, then the y-intercept

regression coefficient has no particular meaning. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 35. The sign of the correlation coefficient in a simple linear regression model will always be the same as the

sign of the y-intercept coefficient .

Chapter 12 - Simple Linear Regression and Correlation a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 36. The standard error of the estimate in a simple linear regression model measures the variation in the slope

coefficient from sample to sample. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 37. In a simple linear regression model, if the independent and dependent variables are negatively related, then

the standard error of the estimate will also be negative. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/9/2019 1:48 AM 38. In a simple linear regression model, if the regression model is statistically significant, then the regression

slope coefficient is significantly greater than zero. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 39. If a simple linear regression model is developed based on a sample where the independent and dependent

variables are known to be positively related, then the sign of the slope regression coefficient will be also positive.

Chapter 12 - Simple Linear Regression and Correlation a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/9/2019 1:49 AM 40. If a simple linear regression model is developed based on a sample where the independent and dependent

variables are known to be negatively related, then the sum of squares for error will be also negative. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/9/2019 1:50 AM 41. In a simple linear regression model, if the value of the coefficient of determination is .90, then the

correlation coefficient between the two variables will be .81. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/23/2019 3:27 AM 42. The value of the sum of squares for regression SSR can never be smaller than 0. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/23/2019 3:27 AM 43. The value of the sum of squares for regression SSR can never be smaller than 1. a. True b. False

Chapter 12 - Simple Linear Regression and Correlation ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 44. If all the values of an independent variable x are equal, then regressing a dependent variable y on x will

result in a coefficient of determination of zero. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 45. In a simple linear regression model, testing a hypothesis or a confidence interval for β, we can find out is

there a linear relationship between x and y. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/23/2019 3:51 AM 46. When the actual values y of a dependent variable and the corresponding predicted values

are the same, the

standard error of estimate will be 0.0. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 2:47 AM 47. If there is no linear relationship between two variables x and y, the coefficient of determination must be 1.0. a. True b. False

Chapter 12 - Simple Linear Regression and Correlation ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 48. The value of the sum of squares for regression SSR can sometimes be larger than the value of sum of

squares for error SSE. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/23/2019 3:52 AM 49. When the actual values y of a dependent variable and the corresponding predicted values

are the same, the

standard error of estimate will be -1. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 2:47 AM 50. In a simple linear regression problem, the least squares line is

= -3.75 + 1.25x, and the coefficient of

determination is 0.81. The coefficient of correlation must be -0.90. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 2:48 AM 51. In a simple linear regression analysis, if the t-test statistic for testing the significance of the regression model

is 3.4, then the F-test statistic from the ANOVA table for regression will be 11.56. a. True b. False

Chapter 12 - Simple Linear Regression and Correlation ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 52. In a simple linear regression model, if you found that the true regression coefficient is significantly greater

than zero, then you may also conclude that the two variables are positively correlated. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 53. In a simple linear regression problem, if the coefficient of determination is 0.95, this means that 95% of the

variation in the independent variable x can be explained by regression line. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 54. In a regression setting, which, if any, of the following is not an assumption about the random error ? a. The errors are linearly correlated. b. The errors are normally distributed with a mean of 0 and a common variance

c. The errors are independent in a probabilistic sense. d. All of these are assumptions about the random error. e. None of these. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 55. In a simple linear regression problem, if the coefficient of determination is 0.96, this means that: a. 96% of the y values are positive

Chapter 12 - Simple Linear Regression and Correlation b. 96% of the total variation in y can be explained by the regression line c. 96% of the x values are equal d. 90% of the total variation in x can be explained by regression line e. 90% of the total variation in y can be explained by the regression line ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 56. If the sum of squares for error (SSE) is equal to zero, then the coefficient of determination ( ) must be: a. 1.5 b. 1.0 c. 0.0 d. -1.0 e. 100 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 57. A regression analysis between sales (y in $1000) and advertising (x in $100) resulted in the following least

squares line: = 82 +7x. This implies that if advertising is $900, then the predicted amount of sales (in dollars) is: a. $6,382 b. $88,300 c. $145,000 d. $82,063 e. $6,382,000 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 2:50 AM 58. If all of the values of an independent variable x are equal, then regressing a dependent variable y on this

independent variable x will result in a coefficient of determination ( ) equal to: a. -1.3

Chapter 12 - Simple Linear Regression and Correlation b. -1.0 c. 0.0 d. 1.0 e. 1.3 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 59. For the values of the coefficient of determination listed below, which one yields the greatest value of sum of

squares for regression given that the total sum of squares is 200? a. 0.90 b. -0.90 c. 0.00 d. 0.98 e. -0.98 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 60. In a simple linear regression problem, suppose the sum of squares for regression (SSR) is 90. Which of the

following must be true? a. The correlation coefficient is 0.9. b. The coefficient of determination is 0.81. c. The total sum of squares (Total SS) is at least 90. d. The sum of squares for error (SSE) is at most 90. e. The coefficient of determination is 90. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 61. A regression analysis between weight (y in pounds) and height (x in inches) resulted in the following least

squares line: expected to:

= 128 + 6x. This implies that if the height is increased by 1 inch, the weight on average is

Chapter 12 - Simple Linear Regression and Correlation a. increase by 1 pound b. decrease by 1 pound c. increase by 6 pounds d. decrease by 6 pounds e. increase by 134 pounds ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 2:51 AM 62. In (all types of) regression analysis, a variable whose value is known and is being used to explain or predict

the value of another variable is called: a. an independent variable b. a predicted variable c. a dependent variable d. a response variable e. all of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 63. In regression analysis, if the values of the dependent variable, y, decrease with larger values of the

independent variable, x, the variables are said to have: a. a direct relationship b. a nonsense correlation c. a deterministic relationship d. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 64. Which of the following correctly describes an estimated regression line? a. It might be represented by the equation

. b. It is a line calculated from census data by the method of least squares.

Chapter 12 - Simple Linear Regression and Correlation c. The values of a and b found in the equation of the estimated regression line represent the line's slope

and intercept, respectively. d. None of these. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 2:51 AM 65. In the probabilistic model y = α + βx + ε, the line of means? a. is the first part of the equation, α + βx, that describes the average value of y for a given value of x. b. is a line calculated from census data by the method of least squares. c. is a line where the values of a and b found in the equation of the estimated regression line represent

the line's slope and intercept, respectively. d. None of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/23/2019 4:49 AM 66. A measure of how well an estimated regression line fits the sample data on which it is based, denoted by

(and equal to the proportion of the total variation in the values of the dependent variable, y, that can be explained by the association of y with x as measured by the estimated regression line) is known as: a. the sample coefficient of variation b. the sample of coefficient of correlation c. the sample coefficient of determination d. the sample coefficient of non-determination e. none of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 67. Which of the following is not an assumption for the simple linear regression model? a. The distribution of the error terms will be skewed to left or right depending on the values of the

dependent variable. b. The error terms have equal variances for all values of the independent variable. c. The error terms are independent of each other.

Chapter 12 - Simple Linear Regression and Correlation d. The mean of the dependent variable for all levels of the independent variable can be connected by a

straight line. e. None of these. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 68. In a simple linear regression analysis, if SSE = 27, Total SS = 63, then the percentage of the variation in the

dependent variable y that is explained by the independent variable x is about: a. 43% b. 27% c. 63% d. 57% e. 36% ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 69. In a simple linear regression analysis, the standard error of the slope is: a. a measure of the amount of change in the dependent variable y for a one unit change in the

independent variable x b. a measure of the variation in the regression slope from sample to sample c. the square root of the standard error of the estimate d. the square of the standard error of the estimate e. all of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 70. Which of the following statements is true? a. In a simple linear regression model, if the regression slope coefficient is negative, then the standard

error of the estimate will be positive. b. In a simple linear regression model, the regression slope coefficient will have the same sign as the correlation coefficient.

Chapter 12 - Simple Linear Regression and Correlation c. The independent variable is not useful in predicting the response variable, if the slope of the line of

means equals 0. d. All of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/23/2019 5:00 AM 71. If an estimated regression line has a y-intercept of 10 and a slope of 4, then when x = 2 the actual value of y

is: a. 18 b. 15 c. 14 d. unknown e. 2 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 72. Given the least squares regression line

= 5 - 2x:

a. the relationship between x and y is positive b. the relationship between x and y is negative c. as x increases, so does y d. as x decreases, so does y e. y is the square of x ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 2:53 AM 73. A regression analysis between weight (y in pounds) and height (x in inches) resulted in the following least squares line: = 120 + 5x. This implies that if the height is increased by 1 inch, the weight, on average, is expected to: a. increase by 1 pound b. decrease by 1 pound c. increase by 5 pounds

Chapter 12 - Simple Linear Regression and Correlation d. increase by 24 pounds e. increase by 125 pounds ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 2:53 AM 74. A regression analysis between sales (in $1000) and advertising (in $100) resulted in the following least

squares line: = 75 + 6x. This implies that if advertising is $800, then the predicted amount of sales (in dollars) is: a. $4875 b. $123,000 c. $487,500 d. $12,300 e. $79,800 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 2:54 AM 75. A regression analysis between sales (in $1000) and advertising (in $) resulted in the following least squares

line:

= 80,000 + 5x. This implies that:

a. an increase of $1 in advertising is expected, on average, to result in an increase of $5 in sales b. an increase of $5 in advertising is expected, on average, to result in an increase of $5,000 in sales c. an increase of $1 in advertising is expected, on average, to result in an increase of $80,005 in sales d. an increase of $1 in advertising is expected, on average, to result in an increase of $5,000 in sales e. all of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 2:54 AM 76. In the simple linear regression model, the slope represents: a. the value of y when x = 0 b. the average change in y per unit change in x

Chapter 12 - Simple Linear Regression and Correlation c. the value of x when y = 0 d. the average change in x per unit change in y e. all of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 77. In regression analysis, the residuals represent the: a. difference between the actual y values and their predicted values b. difference between the actual x values and their predicted values c. square root of the slope of the regression line d. change in y per unit change in x e. difference between the actual x and y values ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 78. In a simple linear regression problem, the following statistics are calculated from a sample of 10

observations: = 2250, sx = 10, ∑x = 50, ∑y = 75. The least squares estimates of the slope and y-intercept are respectively: a. 1.5 and 0.5 b. 2.5 and 1.5 c. 1.5 and 2.5 d. 2.5 and -5.0 e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/9/2019 2:20 AM 79. If a simple linear regression model has no y-intercept, then: a. all values of x are zero b. all values of y are zero c. all values of y are equivalent to values of x

Chapter 12 - Simple Linear Regression and Correlation d. when x = 0 so does y e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/23/2019 6:01 AM 80. In the least squares regression line

= 3 - 2x, the predicted value of y equals:

a. 1.0 when x = -1.0 b. 2.0 when x = 1.0 c. 2.0 when x = -1.0 d. 1.0 when x = 1.0 e. 1.0 when x = 2.0 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 2:55 AM 81. The least squares method for determining the best fit minimizes: a. total variation in the dependent variable b. sum of squares for error c. sum of squares for regression d. sum of squares for the x values e. all of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/23/2019 7:02 AM 82. In a simple linear regression problem, the following sum of squares are produced:

. The percentage of the variation in y that is explained by the variation in x is: a. 25% b. 75% c. 33%

Chapter 12 - Simple Linear Regression and Correlation d. 50% e. 150% ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 3:00 AM 83. In simple linear regression, most often we perform a two-tail test of the population slope

to determine whether there is sufficient evidence to infer that a linear relationship exists. The null hypothesis is stated as: a. b. c. d.

e. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 84. Testing whether the slope of the population regression line could be zero is equivalent to testing whether: a. the sample coefficient of correlation could be zero b. the standard error of estimate could be zero c. the population coefficient of correlation could be zero d. the sum of squares for error could be zero e. all of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 85. Given that

500,

, sxy = 100, and n = 6, the residual error is:

Chapter 12 - Simple Linear Regression and Correlation a. 12.247 b. 24.933 c. 30.2076 d. 11.180 e. 10 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/23/2019 7:29 AM 86. The symbol for the population coefficient of correlation is: a. r b. c. d. e. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 87. Given that the sum of squares for error is 60 and the sum of squares for regression is 140, then the

coefficient of determination is: a. 0.429 b. 0.300 c. 0.700 d. 0.837 e. 1 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 88. A regression line using 25 observations produced SSR = 118.68 and SSE = 56.32. The residual standard

error is: a. 2.1788

Chapter 12 - Simple Linear Regression and Correlation b. 1.5648 c. 1.5009 d. 2.2716 e. 2.007 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 3:23 AM 89. Given the least squares regression line

= -2.48 + 1.63x, and a coefficient of determination of 0.81, the

coefficient of correlation is: a. -0.85 b. 0.85 c. -0.90 d. 0.90 e. -0.81 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 3:25 AM 90. If the coefficient of determination is 0.975, then the slope of the regression line: a. must be positive b. must be negative c. could be either positive or negative d. must be 0 e. none of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 91. Which value of the coefficient of correlation r indicates a stronger correlation than 0.65? a. 0.55 b. -0.75 c. 0.60

Chapter 12 - Simple Linear Regression and Correlation d. -0.45 e. -0.55 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 92. In regression analysis, if the coefficient of determination is 1.0, then: a. the sum of squares for error must be 1.0 b. the sum of squares for regression must be 1.0 c. the sum of squares for error must be 0.0 d. the sum of squares for regression must be 0.0 e. all of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 93. The coefficient of determination r2 measures the amount of: a. variation in y that is explained by variation in x b. variation in x that is explained by variation in y c. variation in y that is unexplained by variation in x d. variation in x that is unexplained by variation in y e. all of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 3:34 AM 94. If the coefficient of correlation is 0.90, then the percentage of the variation in the dependent variable y that is

explained by the variation in the independent variable x is: a. 90% b. 81% c. 0.90% d. 0.81% e. none of these

Chapter 12 - Simple Linear Regression and Correlation ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 95. Let x be the area (in square feet) to be covered with blacktop and let y be the time (in minutes) it takes a

construction crew to completely cover the area. The simple linear regression model relates x and y where the least squares estimates of the regression parameters are b = 0.207 and a = 81.6. What is the least-squares best-fitting regression line? = What is the estimated amount of time it takes to apply 2400 square feet of blacktop? (minutes) What is the average change in time per one square foot increase in area? (minutes) ANSWER:

81.6 + 0.207x; 578.4; 0.207

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 3:37 AM 96. Let x be the weight (in tons) of a load of lumber and y be the time (in hours) it takes to load it on a truck. A

simple linear regression model relates x and y where the least squares estimates of the regression parameters are b = 6.5 and a = 3.3. What is the least-squares best-fitting regression line? = What is the average change in time per one ton increase in weight? (hours) What is the estimated time it takes to load 9 tons of lumber? (hours) Interpret the y -intercept of the regression line.

Chapter 12 - Simple Linear Regression and Correlation

ANSWER:

3.3+6.5x; 6.5; 61.8; The estimated time it takes to load zero tons of lumber on a truck is 3.3 hours. Of course this does not have any practical sense.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 3:38 AM 97. Let x be the number of pieces of furniture in a delivery truck and y be the time (in hours) it takes the delivery

person to deliver all the pieces of furniture. A simple linear regression analysis related x and y where the least squares estimates of the regression parameters are a = 1.85 and b = 0.55. What is the least squares best-fitting regression line? = What is the slope of the equation?

Interpret the slope of the equation. Does a positive slope make practical sense? Justify your answer.

What is the y-intercept?

Interpret the y-intercept, does this make sense?

Use the least squares regression line to estimate the time it should take to deliver 10 pieces of furniture. (You may assume that 10 is in the range of the data.) (hours) ANSWER:

1.85 + 0.55x; 0.55; This means the average increase in time per one unit increase of furniture is 0.55 hours; 1.85; This means that the time it takes to deliver 0 pieces of furniture is 1.85. This does not make sense.; 7.35

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic

Chapter 12 - Simple Linear Regression and Correlation DATE CREATED: DATE MODIFIED:

2/4/2019 9:42 AM 4/24/2019 3:40 AM

98. A company manager is interested in the relationship between x = number of years that an employee has been

with the company and y = the employee's annual salary (in thousands of dollars). The following MINITAB output is from a regression analysis for predicting y from x for n = 15 data points.

What is the least squares regression equation? = What are the least squares estimates of the slope?

What are the least squares estimates of the y-intercept?

Interpret the estimated slope.

Interpret the estimated y-intercept.

What is the value of

What is the value of the sum of squares for error (SSE)?

Find the coefficient of determination.

Interpret the coefficient of determination.

Chapter 12 - Simple Linear Regression and Correlation

Determine whether a linear relationship exist between x and y. Test using = 0.05. What is the p-value?

Conclude:

A linear relationship ANSWER:

exist between x and y. 16.8221 + 0.64983x; .64983; 16.8221; For each additional year an employee is with this company, his or her salary increases, on average, by $650.; An employee just starting a job with this company, i.e., 0 years, has a starting salary of $16,820.; .653; 8.489; .979; This means that 97.9% of the total variation in y (the employee’s annual salary) is accounted for by regression on x (number of years that an employee has been with the company).; 0; Reject the null hypothesis; does

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 4:34 AM 99. A scientist is studying the relationship between wind velocity (x) and DC output of a windmill (y). The

following MINITAB output is from a regression analysis for predicting y from x.

What is the least squares regression line? = Predict the DC output for a wind velocity of 22 mph.

Chapter 12 - Simple Linear Regression and Correlation

What is the value of the sum of squares for error?

One of the assumptions about the random error in the regression model is that the values of have a common variance equal to . What is the best estimator of ?

What is the coefficient of determination?

Determine whether a linear relationship exist between x and y. Test using = 0.05. What is the p-value?

Conclude:

A linear relationship ANSWER:

exist between x and y. -.1346 + .28996x; 6.2445; .7116; .2435; 88.3%; 0; Reject the null hypothesis; does

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 4:35 AM 100. A scientist is studying the relationship between x = inches of annual rainfall and y = inches of shoreline

erosion. One study reported the following data. Use the following MINITAB output to answer the questions below.

Chapter 12 - Simple Linear Regression and Correlation

What is the equation of the estimated regression line? = Interpret the estimated slope of the regression line.

Determine whether the simple linear regression model useful for predicting erosion from a given amount of rainfall. What is the p-value?

Conclude:

A linear relationship

exist between x and y.

The simple linear regression model rainfall. Identify the coefficient of determination.

Interpret the coefficient of determination.

useful for predicting erosion from a given amount of

Chapter 12 - Simple Linear Regression and Correlation

ANSWER:

-1.7359 + 0.073099x; For each additional inch of annual rainfall, the shoreline erodes 0.0731 inch, on average.; 0; Reject the null hypothesis; does; is; .988; 98.8% of the total variation in y (inches of shoreline erosion) is accounted for by regression on x (inches of annual rainfall).

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 4:33 AM 101. The general manager of a chain of furniture stores believes that experience is the most important factor in

determining the level of success of a salesperson. To examine this belief, she records last month's sales (in $1,000s) and the years of experience of 10 randomly selected salespeople. These data are listed below.

Determine the standard error of estimate. sr = Describe what this statistic tells you about the regression line.

Determine the coefficient of determination. r2 = Discuss what its value tells you about the two variables.

Calculate the Pearson correlation coefficient.

Chapter 12 - Simple Linear Regression and Correlation

r= Why does the correlation coefficient have the sign it has?

Conduct a test of the population slope to determine at the 5% significance level whether a linear relationship exists between years of experience and sales. Test statistic: t= Rejection Region: Reject H0 if | t | > Conclusion:

A linear relationship ANSWER:

between years of experience and sales. 1.5724; The model’s fit is good.; 0.9536; 95.36% of the variation in sales is explained by the variation in years of experience of the salesperson.; 0.9765; It has a positive sign since the slope of the regression line ( = 1.0817) is positive.; 12.8258; 2.306; Reject the null hypothesis; exists

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 4:24 AM 102. A professor of economics wants to study the relationship between income (y in $1000s) and education (x in

years). A random sample eight individuals is taken and the results are shown below.

Determine the standard error of estimate. sr = Describe what this statistic tells you about the regression line.

Chapter 12 - Simple Linear Regression and Correlation

Determine the coefficient of determination. r2 = Discuss what its value tells you about the two variables.

Calculate the Pearson correlation coefficient. r= Why does the correlation coefficient have the sign it has?

Conduct a test of the population slope to determine at the 5% significance level whether a linear relationship exists between years of education and income. Test statistic: t= Rejection Region: Reject H0 if | t | > Conclusion:

A linear relationship ANSWER:

between years of education and income. 2.436; The model’s fit to these data is good.; 0.9223; 92.03% of the variation in income is explained by the variation in years of education.; 0.9604; It has a positive sign since the slope of the regression line ( = 2.9098) is positive.; 8.437; 2.447; Reject the null hypothesis; exists

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 4:32 AM 103. A scientist is studying the relationship between x = density (in number per square meter) of aspen trees

around a pond and y = beaver abundance. The following statistical software output is from a regression analysis for predicting y from x.

Chapter 12 - Simple Linear Regression and Correlation

What is the least-squares regression equation? = What is the estimated slope? b= What is the estimated y-intercept? a= What is the value of the sum of squares for error?

What is the value of the coefficient of determination?

What is the percentage of variation in beaver abundance accounted for by regression on the density of aspen trees?

ANSWER:

0.52381x + 2.5595; .52381; 2.5595; 1.405; .97; 97

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 4:40 AM 104. Evidence supports using a simple linear regression model to estimate a person's weight based on a person's

height. Let x be a person's height (measured in inches) and y be the person's weight (measured in pounds). A random sample of eleven people was selected and the following data recorded:

Chapter 12 - Simple Linear Regression and Correlation

The following output was generated for the data:

Based on the scatterplot above, does a simple linear regression model seem appropriate?

Justify your answer.

Use the printout to find the least-squares prediction line. = Based on the printout, do there appear to be any outliers in the data?

Justify your answer.

Consider the following residual plot of the residuals versus the fitted values.

Chapter 12 - Simple Linear Regression and Correlation

What conclusion, if any, can be drawn from the plot?

Consider the following normal probability plot of the residuals.

What conclusion can be drawn from the plot?

Based on the previous two plots, should you use the model in the computer printout to predict weight?

Justify your answer.

Chapter 12 - Simple Linear Regression and Correlation

ANSWER:

Yes; The data appears to be reasonably linear so a simple linear regression model seems appropriate.; 4.1774x - 147.64; Yes; The 2nd and 11th observations are suspect outliers since the standardized residuals are more than two standard deviations away from the mean of 0.; The residual plot shows a definite cyclical pattern indicating that the errors are not independent.; The plot indicates a departure from normality of the errors since the plot is not even close to a line.; No; The basic assumptions of independent and normally distributed errors has been violated.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 5:09 AM 105. A university admissions committee was interested in examining the relationship between a student's score

on the SAT exam, x, and the student's grade point average, y, (GPA) at the end the student's freshman year of college. The committee selected a random sample of 25 students and recorded the SAT score and GPA at the end of the freshman year of college for each student. Use the following output that was generated using Minitab to answer the questions below:

Use the printout to find the least-square prediction line. = Find the estimated GPA at the end of the freshman year for a student who scored 1175 on the SAT exam.

Chapter 12 - Simple Linear Regression and Correlation

What is the coefficient of determination?

Interpret the coefficient of determination.

Use the p-value approach to test the usefulness of the linear regression model at the 0.05 level of significance. p-value:

Conclude:

There a significant linear relationship between a student's SAT score and the student's GPA at the end of the freshman year of college. ANSWER: 0.0035x - 1.0851; 3.0274; .918; 91.8% of the total variation in GPA can be explained by regression on SAT score.; 0; Reject the null hypothesis; is POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 5:10 AM 106. A study was conducted to determine the effect of extra help sessions based on students ability to avoid

mistakes on a 20- multiple choice test. The data shown below represent the number of extra help sessions attended (x) and the average number of mistakes (y) recorded.

Use the regression formulas to find the least-squares line for the data. = Plot the six points and graph the line.

Chapter 12 - Simple Linear Regression and Correlation

Does the line appear to provide a good fit to the data points?

Use the least-Squares line to predict the value of y when x = 3.5.

Do the data provide sufficient evidence to indicate that y and x are linearly related at the 1% level of significance? p-value:

Conclude:

y and x

linearly related.

Calculate the coefficient of determination. r2 = What information does this value give about the usefulness of the linear model?

ANSWER:

-0.55714x + 6.5;

;

Yes; 4.55; .000248; Reject the null hypothesis; are; 0.9744; The total variation in y is reduced by 97.44% by using the regression equation rather than y-bar to predict the response y. POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic

Chapter 12 - Simple Linear Regression and Correlation DATE CREATED: DATE MODIFIED:

2/4/2019 9:42 AM 4/9/2019 2:34 AM

107. A medical statistician wanted to examine the relationship between the amount of sunshine (x) in hours, and

incidence of skin cancer (y). As a result of the experiment he found that the number of skin cancers detected per 100,000 of population and the average daily sunshine in eight counties around the country. These data are shown below.

Determine the least squares regression line. = Draw a scatter diagram of the data and plot the least squares regression line on it.

Estimate the number of skin cancer per 100,000 of population for 6 hours of sunshine.

Calculate the residual corresponding to the pair (x, y) = (8, 15).

ANSWER:

-1.115 + 1.846x;

;

9.961; 1.347 POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:42 AM

Chapter 12 - Simple Linear Regression and Correlation DATE MODIFIED:

4/9/2019 2:36 AM

108. The normal probability plot is a graph that plots the residuals against the expected value of that residual if it

had come from a normal distribution. When the residuals are normally distributed or approximately, so the plot should appear as a straight line, sloping upward at a 45° angle. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/9/2019 2:37 AM 109. In simple linear regression, one can use the plot of residuals versus the fitted values of y to check for a

constant variance as well as to make sure that the linear model is in fact adequate. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 110. Given that n = 37, and the value of the correlation coefficient r = 0.35, then the value of the test statistic

for testing H0: ρ = 0 is t = 2.21. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/11/2019 3:08 AM 111. In regression analysis, a careful study of the differences, , between observed and estimated y values,

given x (in order to decide whether crucial assumptions are fulfilled that allow valid inferences about the true regression line to be made from an estimated regression line) is called residual analysis. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False

Chapter 12 - Simple Linear Regression and Correlation HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 5:14 AM 112. In regression analysis, a graph of each residual against the corresponding fitted value is called a scatter

diagram. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 113. In developing a 90% confidence interval for the average value of y from a simple linear regression problem

involving 12 observations, the appropriate table value would be 1.796. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 114. If all the points in a scatterplot lie on the least squares regression line, then the correlation coefficient must

be 1.0 a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 115. In a simple linear regression problem, the least squares line is

determination is 0.7744. The correlation coefficient must be -0.88. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False

= 2.73 - 1.02x, and the coefficient of

Chapter 12 - Simple Linear Regression and Correlation HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 5:20 AM 116. Simple regression analysis is a statistical technique that establishes an index that provides, in a single

number, a measure of the strength of association between two variables. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 117. If the correlation coefficient between two variables is very close to zero, this means that there is no

relationship between the two variables. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 118. A perfect correlation between two variables will always produce a correlation coefficient of + 1.0. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 119. In simple linear regression analysis, if the correlation coefficient between the independent variable x and

the dependent variable y is -.85, this means that the scatterplot generated by the same data values would show points that would fall on a straight line with slope equal to -.85. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False

Chapter 12 - Simple Linear Regression and Correlation DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 120. If the correlation coefficient for two variables is found to be .094, then the scatterplot will show the data

upward sloping from lower left to upper right. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 121. If there is a negative correlation between the independent variable x and the dependent variable y, then to

test this, the appropriate null and alternative hypotheses would be

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 122. In simple linear regression analysis, if the independent variable x and the dependent variable y are highly

correlated, this does not only mean that they are linearly related, but it also means that a change in x will cause a change in y. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 123. The regression model = 36.5 + 20.1x has been computed based on a sample of 50 observations. One

observation in the sample was (x, y) = (14, 350.9). Given this, the residual value for this observation is 33. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False

Chapter 12 - Simple Linear Regression and Correlation HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 124. In a simple linear regression analysis, it was stated that the correlation between starting salary and years of

experience is 0.80. This indicates that 80% of the variation in starting salary is explained by years of experience. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 125. When regression analysis is used for prediction, the confidence interval for the average y given x will be

wider than the prediction interval for a particular value of y given x. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 126. Large coefficient of determination value will result in a small standard error of the estimate for the

regression model, thus providing prediction intervals that are narrow. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 127. The prediction interval developed from a simple linear regression model will be very narrow when the

value of x used to predict y is equal to the mean value . a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False

Chapter 12 - Simple Linear Regression and Correlation HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 128. In developing a 95% confidence interval for the expected value of y from a simple linear regression

problem involving a sample of size 10, the appropriate table value would be 1.86. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 129. In developing a 80% prediction interval for the particular value of y from a simple linear regression

problem involving a sample of size 12, the appropriate table value would be 1.372. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 130. In developing 90% prediction interval for the particular value of y from a simple linear regression problem

involving a sample of size 14, the appropriate table value would be 2.179. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 131. In order to predict with 95% confidence a particular value of y for a given value of x in a simple linear

regression problem, a random sample of 20 observations is taken. The appropriate table value that would be used is 2.101. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False

Chapter 12 - Simple Linear Regression and Correlation HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 132. The confidence interval estimate of the expected value of y will be narrower than the prediction interval

for the same given value of x and confidence level. This is because there is less error in estimating a mean value as opposed to predicting an individual value. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 133. The confidence interval estimate of the expected value of y will be wider than the prediction interval for

the same given value of x and confidence level. This is because there is more error in estimating a mean value as opposed to predicting an individual value. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 134. In developing a 90% confidence interval for the expected value of y from a simple linear regression

problem involving a sample of size 15, the appropriate table value would be 1.761. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 135. In the simple linear regression model y = α + βx + ε which of the following is true regarding the values of

the random error term ? a. They are independent. b. They have a mean of 0 and a common variance c. They are normally distributed.

, independent of x.

Chapter 12 - Simple Linear Regression and Correlation d. All of these. e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 7:47 AM 136. In the simple linear regression model y = α + βx + ε which of the following is false regarding the values of

the random error term ? a. They are independent. b. They have a mean of 0 and a variance of 1, independent of x. c. They are normally distributed. d. None of these. e. All of these. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 7:49 AM 137. In simple linear regression, the plot of residuals versus fitted values can be used to check for: a. normality b. a constant variance independent of x c. the value of the coefficient of determination d. all of these e. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 7:57 AM 138. In simple linear regression, the plot of residuals versus fitted values a. be free of any patterns b. appear as a random scatter of points about 0 on the vertical axis c. approximately have the same vertical spread for all values d. all of these e. none of these

should:

Chapter 12 - Simple Linear Regression and Correlation ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 7:58 AM 139. Which of the following statements is false regarding the residuals in simple linear regression model? a. They sum to 0. b. They have a mean of 0. c. They have a standard deviation of 1. d. None of these. e. All of these. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 140. In a simple linear regression problem including n = 10 observations, which of the following table values

would be appropriate for a 95% confidence interval estimation for the average value of y? a. 2.228 b. 2.262 c. 2.306 d. 1.860 e. 18.60 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 141. In a regression problem the following pairs of (x, y) are given: (4, 1), (4, -1), (4, 0), (4, -2) and (4, 2). That

indicates that: a. the correlation coefficient is -1 b. the correlation coefficient is 0 c. the correlation coefficient is 1 d. the coefficient of determination is between -2 and 2 e. none of these ANSWER: POINTS:

b 1

Chapter 12 - Simple Linear Regression and Correlation QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 142. The following are coefficients of correlation (r). The one that indicates a strong negative linear relationship

between the two variables of interest is: a. 0.8 b. -0.9 c. 0.9 d. -1.3 e. 1 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 143. The following are coefficients of correlation (r). The one that indicates a strong positive linear relationship

between the two variables of interest is: a. 0.8 b. -0.9 c. 0.9 d. -1.3 e. -1 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 144. Given the least squares regression line

correlation coefficient must be: a. -0.95 b. +0.95 c. +1.38 d. -0.81 e. 0.81 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice

= -4.63 + 1.38x, and a coefficient of determination of 0.9025, the

Chapter 12 - Simple Linear Regression and Correlation HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 8:08 AM 145. An indication of no linear relationship between two variables x and y would be: a. a coefficient of correlation of 1 b. a coefficient of correlation of 0 c. a coefficient of correlation of -1 d. a coefficient of determination of 1 e. 0.5 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 146. In publishing the results of some research work, the following values of the correlation coefficient were

listed. Which one would appear to be incorrect? a. 0.95 b. 0.05 c. 0.00 d. 1.05 e. 0.11 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 147. Which of the following statements about simple correlation analysis are correct? a. When all the points in a scatter diagram lie precisely on the estimated regression line, the sample

coefficient of correlation will equal 0. b. When all the points in a scatter diagram lie precisely on the estimated regression line, the sample coefficient of correlation will show the variables to be perfectly correlated. c. When all the points in a scatter diagram are so widely scattered as to make x completely worthless as a predictor of y, the sample coefficient of correlation will equal 1. d. All of these. e. None of these. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice

Chapter 12 - Simple Linear Regression and Correlation HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 148. In studying the relationship between two variables x and y, a scatterplot can be used to detect which of the

following? a. A positive linear relationship. b. A negative linear relationship. c. A relationship that is not linear. d. All of these. e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 149. If the true correlation between two variables is zero, then which of the following statements is true? a. There is no linear relationship between the two variables. b. There may be no relationship between the two variables. c. Neither “There is no linear relationship between the two variables” nor “There may be no

relationship between the two variables”. d. Both “There is no linear relationship between the two variables” and “There may be no relationship between the two variables”. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 150. If a sample of 25 observations is selected, and the sample correlation coefficient between the variables x

and y is r = 0.525, what is the test statistic value for testing a. About 3.65. b. About 2.96. c. About 3.08. d. About 3.81. e. About 3.96. ANSWER:

POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False

Chapter 12 - Simple Linear Regression and Correlation DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 151. Which of the following is the appropriate null hypothesis to test whether a population correlation is zero? a. b. c. d. e. None of these. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 152. A study of 20 students showed that the correlation between the time spent writing a test and the number of

hours studied the night before the test was 0.35. Using a level of significance equal to 0.05, which of the following statements is true? a. The sample correlation coefficient could be zero since the test statistic does not fall in the rejection

region. b. The null hypothesis that the population mean is equal to zero should not be rejected, and we should conclude that the true correlation coefficient is zero. c. There is not enough statistical evidence to conclude that the true correlation coefficient is different from zero. d. The null hypothesis that the population variance is equal to zero should be rejected, and we should conclude that the true correlation coefficient is zero. e. None of these. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/9/2019 2:55 AM 153. In order to estimate with 95% confidence the expected value of y for a given value of x in a simple linear

regression problem, a random sample of 10 observations is taken. Which of the following t-table values listed below would be used? a. 2.228 b. 2.306 c. 1.860

Chapter 12 - Simple Linear Regression and Correlation d. 1.812 e. 2.812 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 154. Given a specific value of x and confidence level, which of the following statements is correct? a. The confidence interval estimate of the expected value of y can be calculated but the prediction

interval of y for the given value of x cannot be calculated. b. The confidence interval estimate of the expected value of y will be wider than the prediction interval. c. The prediction interval of y for the given value of x can be calculated but the confidence interval estimate of the expected value of y cannot be calculated. d. The confidence interval estimate of the expected value of y will be narrower than the prediction interval. e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 155. In order to predict with 90% confidence the expected value of y for a given value of x in a simple linear

regression problem, a random sample of 10 observations is taken. Which of the following t-table values listed below would be used? a. 2.228 b. 2.306 c. 1.860 d. 1.812 e. 2.812 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 156. The confidence interval estimate of the expected value of y for a given value x, compared to the prediction

interval of y for the same given value of x and confidence level, will be: a. wider

Chapter 12 - Simple Linear Regression and Correlation b. narrower c. the same d. impossible to know ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/9/2019 2:43 AM 157. In order to predict with 99% confidence the expected value of y for a given value of x in a simple linear

regression problem, a random sample of 10 observations is taken. Which of the following t-table values listed below would be used? a. 1.860 b. 2.306 c. 2.896 d. 3.355 e. 2.355 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 158. The width of the confidence interval estimate for the predicted value of y depends on: a. the standard error of the estimate b. the value of x for which the prediction is being made c. the sample size d. all of these e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 159. In order to predict with 80% confidence the expected value of y for a given value of x in a simple linear

regression problem, a random sample of 15 observations is taken. Which of the following t-table values listed below would be used? a. 1.350 b. 1.771

Chapter 12 - Simple Linear Regression and Correlation c. 2.160 d. 2.650 e. 2.260 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 160. In order to predict with 98% confidence the expected value of y for a given value of x in a simple linear

regression problem, a random sample of 15 observations is taken. Which of the following t-table values listed below would be used? a. 1.350 b. 1.771 c. 2.160 d. 2.650 e. 1.750 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 161. If the plot of the residuals is fan shaped, which assumption of regression analysis if violated? a. The values of the random error term are normally distributed. b. The values of the random error term have a mean of 0 and a common variance σ2, independent of x. c. The values of the random error term are independent. d. No assumptions are violated, the graph should resemble a fan. e. The relationship between y and x is linear. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/11/2019 3:32 AM 162. In regression analysis to measure the strength of the relationship between the response variable y and the

predictor variable x is to calculate: a. the test statistic b. both the test statistic and the correlation coefficient

Chapter 12 - Simple Linear Regression and Correlation c. the coefficient of determination d. the standard error of the estimate e. none of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/11/2019 3:49 AM 163. Six points have these coordinates:

The normal probability plot and the residuals versus fitted values plots generated by Minitab are shown below.

Chapter 12 - Simple Linear Regression and Correlation

Does it appear that any regression assumptions have been violated?

Explain.

ANSWER:

No; There is only one data point in each graph that appears somewhat unusual. There is no reason to doubt the validity of the regression assumptions.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic

Chapter 12 - Simple Linear Regression and Correlation DATE CREATED: DATE MODIFIED:

2/4/2019 9:42 AM 2/4/2019 9:42 AM

164. A microwave manufacturer has collected the data shown below on number of units sold (y) in the

thousands of dollars and the number of ads (x) placed during the month.

Calculate the preliminary sums of squares and cross-products. Sxx = Syy = Sxy = Calculate: SSE = MSE = Determine the least-squares regression line.

= Compute a point estimate of number of units sold if there are 140 ads.

Compute the standard error of the point estimate of number of units sold if there are 140 ads.

Compute a 95% confidence interval for the average number of units sold in all months with 140 ads. Enter (n1, n2) Compute a 95% prediction interval for sales during the next month that happens to be associated with 140 ads. Enter (n1, n2)

Chapter 12 - Simple Linear Regression and Correlation ANSWER:

71079.75; 404.55; 2933.25; 283.5035; 15.750; 6.08+ 0.0413x; 11.857; 0.9885; (9.780, 13.934); (3.264, 20.450)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/10/2019 1:59 AM 165. A company manager is interested in the relationship between x = number of years that an employee has

been with the company and y = the employee's annual salary (in thousands of dollars). The following statistical software output is from a regression analysis for predicting y from x for n = 15 data points.

Find the correlation coefficient. r= There is ANSWER:

_ linear relationship between x and y. 0.989; a strong positive

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 8:00 AM 166. The manager of an ice cream store is interested in examining the relationship between sales of ice cream (in

gallons per day) and maximum temperature of the day. The vendor records the following data for a random sample of five days in the summer, where y is number of gallons of ice cream sold per day and x is maximum temperature, in degrees Fahrenheit, recorded for the day:

The following summary information were computed:

Chapter 12 - Simple Linear Regression and Correlation

Find and interpret the correlation between maximum daily temperature and daily sales of ice cream. Syy = What is the correlation coefficient? r= There is ANSWER:

_ linear relationship between daily sales of ice cream and maximum daily temperature. 20.572; 0.971; a strong positive

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/24/2019 7:30 AM 167. A university admissions committee was interested in examining the relationship between a student's score

Determine the correlation between a student's SAT score and GPA at the end of the freshman year.

Since b is

the correlation is

Chapter 12 - Simple Linear Regression and Correlation

Interpret the value.

There is a freshman year.

linear relationship between a student's SAT score and GPA at the end of the

ANSWER:

positive; positive; strong positive

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 168. The general manager of a chain of furniture stores believes that experience is the most important factor in

determining the level of success of a salesperson. To examine this belief she records last month's sales (in $1,000s) and the years of experience of 10 randomly selected salespeople. These data are listed below.

Predict with 95% confidence the monthly sales of a salesperson with 10 years of experience.

CI =

Enter (n1, n2) in thousands

Estimate with 95% confidence the average monthly sales of all salespersons with 10 years of experience.

CI =

Enter (n1, n2) in thousands

Which interval in the previous two questions is narrower: the confidence interval estimate of the expected value of y or the prediction interval for the same given value of x (10 years) and same confidence level?

Why?

Chapter 12 - Simple Linear Regression and Correlation

ANSWER:

(15.628, 23.266); (18.248, 20.646); confidence interval; Because there is less error in estimating a mean value as opposed to predicting an individual value.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 2/4/2019 9:42 AM 169. A professor of economics wants to study the relationship between income (y in $1000s) and education (x in

years). A random sample eight individuals is taken and the results are shown below.

Predict with 95% confidence the income of an individual with 10 years of education. CI =

Enter (n1, n2) in thousands

Estimate with 95% confidence the average income of all individuals with 10 years of education. CI =

Enter (n1, n2) in thousands

Why?

ANSWER:

(36.806, 42.622); (33.083, 46.346); confidence interval; Because there is less error in estimating a mean value as opposed to predicting an individual value.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/10/2019 2:21 AM 170. An ardent fan of television game shows has observed that, in general, the more educated the contestant, the

less money he or she wins. To test her belief she gathers data about the last eight winners of her favorite game show. She records their winnings in dollars and the number of years of education. The results are as follows.

Chapter 12 - Simple Linear Regression and Correlation

Predict with 95% confidence the winnings of a contestant who has 15 years of education. CI =

Enter (n1, n2)

Predict with 95% confidence the winnings of a contestant who has 10 years of education. CI =

Enter (n1, n2)

Estimate with 95% confidence the average winnings of all contestants who have 15 years of education. CI =

Enter (n1, n2)

Estimate with 95% confidence the average winnings of all contestants who have 10 years of education. CI = ANSWER:

Enter (n1, n2) (332.504, 462.496); (737.196, 949.471); (238.294, 556.706); (663.369, 1023.298)

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:42 AM DATE MODIFIED: 4/11/2019 4:37 AM 171. A large retail chain is planning to open a new store. The management of the retail chain has estimates of turnover of goods and, accordingly, revenue that the new store could be getting, taking into account the competition. It is also necessary to determine the number of staff required to ensure the operation of the store. To do this, a sample of random stores of this retail chain in different parts of the cities from this region was taken. The relationship between the number of staff and the revenue for this sample was determined.

In this equation, is the day revenue of a store in millions of dollars, x is the number of staff working in this store. The ANOVA table for this test is presented below. ANOVA Regression

df 1

SS 5.596533

MS 5.596533

F 298.4388

Significance F 0.000000

Chapter 12 - Simple Linear Regression and Correlation Residual Total

15 16

0.281291 5.877824

0.018753

Using these data, determine the t-statistic for the obtained linear regression. Make a conclusion about the significance of this regression model. Test at the 5% level of significance. a. ; there is enough evidence to conclude that there is a significant linear regression. b. ; there is enough evidence to conclude that there is a significant linear regression. c. ; there is not enough evidence to conclude that there is a significant linear regression. d. ; there is not enough evidence to conclude that there is a significant linear regression. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 3:57 AM DATE MODIFIED: 2/6/2019 8:47 AM 172. The environmental service of a small industrial center reported that over the past ten years the environmental situation in the region had noticeably improved. However, a local media doubted the correctness of the reasons for this fact specified in the report. A local newspaper journalist conducted a study about the relationship between the increase in the proportion of the rural population in the region and the improvement in environmental performance. The statistical studies conducted on randomly presented samples give correlation coefficient 0.903. The journalist concluded that the counter-urbanization of the population was the real reason for the improvement of the environmental situation in the region. What can be said about these conclusions? a. The high correlation coefficient means a strong relationship between these facts and, therefore, the counterurbanization of the population causes the improvement of the environmental situation in the region. b. The high correlation coefficient means a strong relationship between these facts; it does not mean that the counter-urbanization of the population cause the improvement of the environmental situation in the region. c. A local newspaper journalist cannot conduct a proper statistical study. The obtained data are biased. d. The correlation coefficient of 0.903 is not large enough to conclude that there is any relationship between the two facts. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 6:11 AM DATE MODIFIED: 2/6/2019 6:12 AM 173. According to Hooke's law, the force needed to extend or compress a spring by some distance scales linearly with respect to this distance. A student physicist conducted an experiment to verify this law. The results of this experiment are presented in the table below. x, m 0.01 0.02 0.03

F, N –0.8 –1.7 –2.4

Chapter 12 - Simple Linear Regression and Correlation 0.04 0.05 0.06 0.07 0.08 0.09 0.10

–3.1 –4.0 –4.9 –5.6 –6.3 –7.2 –8.1

However, the student decided to cheat and finish the table by using extrapolated data. Having found the coefficient, the values up to x = 0.3 m were entered into the table. Here is the “extrapolated” data table. x, m 0.11 0.12 0.13 0.14 0.15 0.16 0.17 0.18 0.19 0.20 0.21 0.22 0.23 0.24 0.25 0.26 0.27 0.28 0.29

F, N –8.8 –9.7 –10.5 –11.2 –12.1 –12.9 –13.6 –14.4 –15.2 –16.1 –16.9 –17.6 –18.4 –19.3 –20.0 –20.8 –21.7 –22.3 –23.3

0.30

–24.1

The professor immediately noticed the student’s cheat. What didn’t the student take into account? a. The student incorrectly calculated the linear coefficient. If the student had used the right coefficient, the data in the table would have been correct. b. The student conducted a very rough experiment and received inaccurate data. This led to an increase in error for large -values and the professor noticed this. c. There is no reason to believe that the relationship for data beyond the measurement interval remains linear. (Hooke’s law works for small x-values.) d. The student simply had no luck; the method of extrapolating data always works. e. There are no objective reasons to accuse the student of cheating. ANSWER: c POINTS: 1

Chapter 12 - Simple Linear Regression and Correlation QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 6:12 AM DATE MODIFIED: 2/6/2019 6:25 AM

Chapter 13 - Multiple Linear Regression Analysis 1. The coefficient of determination R2 represents the proportion of the total variation in y that can be explained

by the regression of y on x1, x2 ,...,xk. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 5:54 AM 2. Assume that a company is tracking their advertising expenditures as they relate to television (

) and radio advertising ( ). The owner of the company believes that it would improve the regression model to add a third variable that represents the sum of the advertising on radio and television ( = + ). This assessment is generally correct. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 2/4/2019 9:43 AM 3. Having a large number of predictors in a regression model guarantees that the model fits well. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/10/2019 5:14 AM 4.

is an example of a multiple regression model.

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 2/4/2019 9:43 AM

Chapter 13 - Multiple Linear Regression Analysis 5. The more predictors are added to a regression model, the larger the coefficient of determination R2 value will

be. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/10/2019 5:15 AM 6.

is an example of a linear regression model.

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/15/2019 6:57 AM 7. In multiple regression, the prediction equation

is the line that minimizes SSE, the sum of squares of the deviations of the observed values y from the predicted values . a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/10/2019 5:28 AM 8. Let

be the least squares estimate of the population coefficient

the test statistic given by

has an F distribution with k and n-k-1 degrees of freedom, where n is the

number of observations and k is the number of predictor variables. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM

. If the regression assumptions hold true,

Chapter 13 - Multiple Linear Regression Analysis DATE MODIFIED: 4/10/2019 5:32 AM 9. Residuals are the deviations between the observed values of y and their predicted values a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/10/2019 5:35 AM

10. Suppose that one equation has 3 explanatory variables and an F-ratio of 52. Another equation has 5

explanatory variables and an F-ratio of 40. The first model will always fit better than the second model. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/10/2019 5:37 AM 11. For the test of the usefulness of a multiple linear regression model involving 5 predictor variables and 25

observations, the numerator and denominator degrees of freedom for the critical value of F are 4 and 24, respectively. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/10/2019 8:53 AM 12. A multiple regression equation includes 5 predictor variables, and the coefficient of determination is 0.7921.

The percentage of the variation in y that is explained by the regression equation is 89%. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM

Chapter 13 - Multiple Linear Regression Analysis DATE MODIFIED: 4/11/2019 6:02 AM 13. A multiple regression model has the form

in y per unit change in

. The coefficient

is interpreted as the change

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/10/2019 5:46 AM 14. In testing the significance of a multiple regression model in which there are three independent variables, the

null hypothesis is

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 6:03 AM 15. Statistical packages print a second

statistic, called the adjusted coefficient of determination, which has been adjusted for the degrees of freedom to take into account the sample size and the number of predictor variables. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/15/2019 9:09 AM 16. In the regression model

in , regardless of the value of a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False

, the value 0.63 is the average change in y per unit change .

Chapter 13 - Multiple Linear Regression Analysis HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/15/2019 9:11 AM 17. A multiple regression model involves 40 observations and 4 independent variables produces Total SS =

2,000 and SSR = 1,608. The value of MSE is 11.2. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/15/2019 9:15 AM 18. In the regression model a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 6:08 AM

, the value -0.75 is the intercept.

19. Multiple regression is the process of using several independent variables to predict a number of dependent

variables. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 2/4/2019 9:43 AM 20. In multiple regression, the descriptor "multiple" refers to more than one dependent variable. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM

Chapter 13 - Multiple Linear Regression Analysis DATE MODIFIED: 2/4/2019 9:43 AM 21. For each x term in the multiple regression equation, the corresponding is referred to as a partial regression

coefficient. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 6:09 AM 22. In a multiple regression problem, the regression equation is

for y when

and

. The estimated value

is 48.

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/10/2019 6:05 AM 23. In the regression model a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/10/2019 6:09 AM

, the value 0.08 is the y-intercept.

24. In testing the significance of a multiple regression model in which there are three independent variables, the

alternative hypothesis is a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 6:10 AM

Chapter 13 - Multiple Linear Regression Analysis 25. In a multiple regression problem involving 24 observations and three independent variables, the estimated

regression equation is . For this model, value of the F statistic for testing the significance of the model is 15.102.

and

. Then, the

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 6:16 AM 26. A multiple regression equation includes 5 independent variables, and the coefficient of determination is

0.81. Then, the percentage of the variation in y that is explained by the regression equation is 90%. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 6:17 AM 27. Multiple regression analysis is a type of regression analysis in which several independent variables are used

to estimate the value of an unknown dependent variable; hence, each of these predictor variables explains part of the total variation of the dependent variable. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 2/4/2019 9:43 AM 28. A partial regression coefficient is the coefficient of a dependent variable in a multiple-regression equation. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM

Chapter 13 - Multiple Linear Regression Analysis DATE MODIFIED: 4/11/2019 6:20 AM 29. A partial regression coefficient gives the partial change in y for a unit change in that independent variable

while holding other independent variables constant. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 6:20 AM 30. The prediction equation

of the deviations of ).

(the estimated response using

is the line that minimizes SSR, the sum of squares ) from (the estimated response without using

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 6:57 AM 31. In regression analysis, a p-value provides the probability (judged by the t-value associated with an estimated

regression coefficient) of

being true, given the claim

: The true regression coefficient equals 0.

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 2/4/2019 9:43 AM 32. A coefficient of determination is a measure of how well an estimated regression plane fits the sample data

on which it is based. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False

Chapter 13 - Multiple Linear Regression Analysis DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 7:37 AM 33. Multiple linear regression is an extension of simple linear regression to allow for more than one dependent

variable. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 2/4/2019 9:43 AM 34. A coefficient of determination is denoted by

and equals the proportion of the total variation that is not

explained by the regression equation. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 7:42 AM 35. In multiple regression analysis, the adjusted coefficient of determination is adjusted for the number of

independent variables and the sample size. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 7:10 AM 36. A multiple regression analysis including 25 data points and 4 independent variables produces Total SS= 400

and SSR = 300. Then, the F statistic is 5. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False

Chapter 13 - Multiple Linear Regression Analysis DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/12/2019 5:21 AM 37. Multicollinearity is present if the response variable is linearly related to one of the predictor variables. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 7:22 AM 38. In a multiple regression analysis involving 50 observations and 5 independent variables, Total SS = 475 and

SSE = 71.25. Then, the coefficient of determination is 0.85. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 7:26 AM 39. A multiple regression model has the form

. As

increases by one unit, holding

constant, the value of will increase by 9 units. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 7:29 AM 40. In the multiple regression model

and

, if were to increase by five units, holding constant, then, the value of would decrease on average by 50 units.

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False

Chapter 13 - Multiple Linear Regression Analysis DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 7:28 AM 41. In multiple regression, a large value of the test statistic F indicates that most of the variation in y is

unexplained by the regression equation and that the model does not fit well. A small value of F indicates that most of the variation in y is explained by the regression equation and that the model is useful. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/10/2019 6:45 AM 42. When an additional predictor variable is introduced into a multiple regression model, the coefficient of

determination adjusted for degrees of freedom can never decrease. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 7:47 AM 43. In multiple regression analysis, when the response surface (the graphical depiction of the regression

equation) hits every single point, the sum of squares for error SSE = 0, and the coefficient of determination 1. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 7:50 AM 44. In multiple regression analysis, the coefficient of determination is sometimes called multiple a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False

Chapter 13 - Multiple Linear Regression Analysis HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 2/4/2019 9:43 AM 45. The coefficient of determination is calculated by dividing the regression sum of squares by the total sum of

squares (SSR/Total SS) and subtracting that value from 1. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 7:52 AM 46. In a multiple regression model involving 5 independent variables, if the total sum of squares is 900, the sum

of squares for regression is 847, and the data set contains 40 points, then, the value of the variation that is unexplained by the predictor variables is 169.4. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/16/2019 6:47 AM 47. The adjusted coefficient of determination is adjusted for the number of independent variables in the model

by using sum of squares rather mean squares. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 2/4/2019 9:43 AM 48. The adjusted value of

is used only to compare two or more regression models that have the same number of independent predictors to determine which one fits the data better. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False

Chapter 13 - Multiple Linear Regression Analysis HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/10/2019 6:52 AM 49. In a multiple regression model, the coefficient of determination (sometimes called multiple

) can be simply computed by squaring the largest correlation coefficient between the dependent variable and any of the independent variables. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/15/2019 9:46 AM 50. In a multiple regression model, there is only one dependent variable and two or more independent variables. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 2/4/2019 9:43 AM 51. The coefficient of determination measures the proportion or percentage of variation in the dependent

variable that is explained by the independent variables included in the model. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/10/2019 9:08 AM 52. In a multiple regression model, the partial regression coefficients measure the average change in the

dependent variable for a one-unit change in the independent variable of interest, with all other independent variables held constant. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False

Chapter 13 - Multiple Linear Regression Analysis HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 8:11 AM 53. Consider a multiple regression model with three independent variables. If the y-intercept is negative, then at

least two of the partial regression slope coefficients will also be negative. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 8:12 AM 54. In a multiple regression model, there are 10 independent variables included in the model. Therefore the

sample size should be equal to 10. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 8:14 AM 55. In a multiple regression model, it is assumed that the values of the random error are normally distributed. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/10/2019 7:05 AM 56. In a multiple regression model, the regression coefficients are calculated such that the quantity

minimized. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False

Chapter 13 - Multiple Linear Regression Analysis DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 8:16 AM 57. A multiple regression model a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/10/2019 7:11 AM

has to be plotted in (k+1) dimensions.

58. In a multiple regression model where four independent variables are included in the model, the percentage of

explained variation in the dependent variable will be equal to the square root of the sum of squares for error. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/16/2019 6:49 AM 59. In a multiple regression model, the adjusted

value measures the explained variation in the dependent variable after taking into account the relationship between the sample size and the number of independent variables in the model. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 2/4/2019 9:43 AM 60. If the value of the coefficient of determination

is large, then the value of the F-test statistic that is used for testing the usefulness of the multiple regression model is small. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False

Chapter 13 - Multiple Linear Regression Analysis DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 8:28 AM 61. If the

value for a multiple regression model with two independent variables and ten observations is .81, then the F statistic will be .90. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/16/2019 6:51 AM 62. If you wish to test the usefulness of a multiple regression model with three independent variables, the

appropriate null and alternative hypotheses are

vs.

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 2/4/2019 9:43 AM 63. A regression model of the form

is called a quadratic model or a second-order

polynomial model. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 2/4/2019 9:43 AM 64. A regression model of the form a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False

is called a third-order polynomial model.

Chapter 13 - Multiple Linear Regression Analysis DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 2/4/2019 9:43 AM 65. To check out the regression model assumption involving normality of the values of random error, it is

appropriate to construct a normal probability plot. If this plot forms a straight line from the lower left-hand corner to the upper right-hand corner, the error terms may be assumed to be normally distributed. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 8:33 AM 66. Consider a multiple linear regression model:

. Which of the following

statements, if any, is true? a.

is the intercept, while

are the partial regression coefficients.

b. The coefficient

measures the change in the dependent variable y for a unit change in other independent variables are held constant. c. are independent predictor variables that are measured without error.

when all

d. All of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 8:34 AM 67. The adjusted coefficient of determination is adjusted for: a. number of regression parameters including b. number of dependent variables and the sample size c. number of predictor variables and the sample size d. correlation coefficient e. number of regression parameters including ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM

and number of dependent variables and the sample size

Chapter 13 - Multiple Linear Regression Analysis DATE MODIFIED: 4/11/2019 8:35 AM 68. Suppose a regression analysis based on the model

= 3.55,

= 13.131, and

with 15 observations produced SSE

= 125.1. Hence, the proportion of the total variability in y that is accounted for by

and

is: a. 0.2704 b. 0.7296 c. 0.9688 d. 0.0312 e. 0.1032

ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 2/4/2019 9:43 AM 69. In a regression setting, which of the following, if any, is true? a. If you add a predictor variable to an existing model, the value of

will either remain the same or increase. However, in selecting a model, you should consider the value of the adjusted as well as .

b. You should always select the model with the smallest . c. You should select a model where all the regression coefficients have p-values greater than 0.05. d. All of the above. e. None of these. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:43 AM DATE MODIFIED: 4/11/2019 8:40 AM 70. In a multiple regression analysis, if the model provides a poor fit, this indicates: a. that the sum of squares for error (SSE) will be large b. that the adjusted coefficient of determination will be close to zero c. that the multiple d. all of the above e. none of these ANSWER: d

will be close to zero

Chapter 13 - Multiple Linear Regression Analysis POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/12/2019 5:32 AM 71. In a multiple regression analysis involving 24 data points, the mean squares for error, MSE, is 2, and the

sum of squares for error, SSE, is 36. The number of the predictor variables must be: a. 7 b. 6 c. 5 d. 4 e. 3 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 72. The test statistic F found in the ANOVA table for testing the usefulness of the regression model is calculated

by: a. MSR / MSE b. MSE / MSR c. Total SS / SSE d. SSR / SSE e. SSE / SSR ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 73. In order to test the validity of a multiple regression model involving 4 predictor variables and 25

observations, the numerator and denominator degrees of freedom ( value of F are: a. 4 and 20 b. 4 and 25 c. 20 and 4 d. 25 and 4 e. 3 and 21 ANSWER:

, respectively) for the critical

Chapter 13 - Multiple Linear Regression Analysis POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 74. In a multiple regression model, the values of the random error term are assumed to: a. be independent b. have a mean of 0, and a common variance c. be normally distributed

for any set of the predictor variables

d. all of these are required assumptions e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM

75. In multiple regression analysis, the expression

yields the:

a. F-test statistic for testing the usefulness of the regression model b. coefficient of determination c. adjusted coefficient of determination (adj) d. t-test statistic for testing each partial regression coefficient e. coefficient of determination and t-test statistic for testing each partial regression coefficient ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/16/2019 5:51 AM 76. In a multiple regression analysis involving 4 predictor variables, and 25 observations, the total sum of

squares is 800, and the error sum of squares is 200. The value of the F-test statistic for testing the usefulness of this model must be: a. 200 b. 50 c. 32 d. 15 e. 12

Chapter 13 - Multiple Linear Regression Analysis ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 77. For a multiple regression model, there are 20 observations and 4 independent predictor variables. The total

sum of squares is 400, and the sum of squares for regression is 350. The coefficient of determination adjusted for degrees of freedom is: a. 87.5% b. 15.83% c. 12.5% d. 84.17% e. 16.54% ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/10/2019 7:48 AM 78. A multiple regression model involves 3 predictor variables and a sample of 20 data points. If we want to test

the usefulness of the model at the 1% significance level, the critical value of the rejection region is: a. 5.93 b. 7.09 c. 5.29 d. 6.30 e. 4,54 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 79. A multiple regression model has the form:

held constant, then on average is expected to: a. increase by 1 unit b. increase by 10 units c. decrease by 3 units d. decrease by 4 units

. As

increases by 1 unit, with

and

Chapter 13 - Multiple Linear Regression Analysis e. decrease by 5 units ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/11/2019 8:46 AM 80. A multiple regression model involves 5 predictor variables and 30 observations. If we want to test the

hypotheses the critical value of the rejection region will be:

at the 5% significance level,

a. 1.711 b. 2.621 c. 2.045 d. 1.699 e. 1.341 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/10/2019 8:05 AM 81. To test the validity of a multiple regression model involving 3 predictor variables, the null hypothesis to be

tested is that: a. b. c. d. e. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 82. For a multiple regression model, the following statistics are given: Total SS = 500, SSE = 60, and n = 20.

The coefficient of determination, expressed as a percentage, is:

Chapter 13 - Multiple Linear Regression Analysis a. 88% b. 12% c. 93.81% d. 77.44% e. 7.51% ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 83. In a regression model involving 40 observations, the following estimated regression model was obtained:

. For this model, the following statistics are given: SSR = 501 and SSE = 99. Then, the value of MSR is: a. 12.525 b. 33 c. 167 d. 15 e. 18.52 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/10/2019 8:13 AM 84. Which of the following statements is correct? a. Simple regression analysis helps us predict the value of one variable from the known value of another

variable. b. Simple correlation analysis helps us measure the overall strength of the linear association between two variables. c. Multiple regression analysis helps us predict the value of one variable from the known values of several other variables. d. All of these. e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/11/2019 8:57 AM

Chapter 13 - Multiple Linear Regression Analysis

85. Which of the following statements is correct regarding the multiple-regression equation:

? a. This equation gives us the estimated value

of the dependent variable for any specified pair of values

of the independent variables. b. The estimated regression coefficient

represents the slope of the line.

c. The estimated regression coefficient

equals the change in estimated

that is associated with a unit

change in and . d. All of the above are correct. e. None of these are correct. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/11/2019 8:58 AM 86. A three-variable multiple regression establishes an estimated multiple regression equation in such a way

that: a. all the estimates derived from it fall on a surface that is called the regression plane b. all the estimates derived from it fall on a surface that is called the regression plane, which is

positioned among the sample points in such a way as to minimize the sum of squares for regression c. all the estimates derived from it fall on a surface that is called the regression plane, which is positioned among the sample points in such a way as to minimize the total sum of squares d. all of the above e. none of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/11/2019 9:05 AM 87. A three-variable multiple regression plane is positioned so as to minimize the sum of squared errors, which

equals: a.

Chapter 13 - Multiple Linear Regression Analysis c.

e. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 88. Which of the following correctly describes a p-value? a. It gives the partial change in y for a unit change in an independent variable while holding other

independent variables constant. b. It equals the probability of being true, given the claim : The true regression coefficient equals 0. c. It is an index of the degree of linear association among more than two variables, equal to the square root of the coefficient of determination. d. It equals the ration of an estimated partial-regression coefficient to its standard error. e. All of these. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/16/2019 5:27 AM 89. Which of the following correctly describes a multiple-regression ANOVA test? a. It is a test of the significance of individual coefficients, rather than of the overall significance of the

regression model. b. It amounts to testing the hypothesis that none of the true regression coefficients is zero and that, therefore, all of the independent predictors help explain the variation of the dependent variable. c. It is a test of the overall significance of regression, rather than a test of the significance of individual coefficients. d. It is a test of the equality of the variances. e. None of these. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice

Chapter 13 - Multiple Linear Regression Analysis HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/16/2019 5:32 AM 90. Which of the following correctly describes the coefficient of determination? a. It is denoted by

and is interpreted as the proportion of the total variation that is explained by the regression of y on the predictor variables. b. It is computed as the ratio of total variation to explained variation. c. It can decrease with the addition of more variables into the regression model. d. It is computed as the ratio of total variation to explained variation and in the case of two independent variables, it can decrease with the addition of more variables into the regression model. e. None of these. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/11/2019 9:09 AM 91. Given a multiple regression with a sum of squares for regression of 850 and a total sum of squares of 1,000,

the coefficient of determination: a. equals .150 b. equals .850 c. equals .387 d. equals .459 e. cannot be determined without additional information ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/10/2019 8:40 AM 92. Which of the following statements is false? a. An adjusted coefficient of determination, denoted by (adj.), is adjusted for the degrees of freedom. b. An estimated partial regression coefficient gives the partial change in for a unit change in that

independent variable while holding other independent variables constant. c. The coefficient of determination takes on values between 0 and 1, inclusive. d. The coefficient of determination never increases with the addition of more variables into the regression model. e. None of these statements is false.

Chapter 13 - Multiple Linear Regression Analysis ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/11/2019 9:14 AM 93. Given MSR = 345 and MSE = 431.25, the value of the F-statistic: a. equals .894 b. equals 1.25 c. equals .80 d. equals .43 e. cannot be computed without additional information ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 94. In testing the validity of a multiple regression model, a large value of the F-test statistic indicates that: a. most of the variation in the independent variables is explained by the variation in y b. most of the variation in y is explained by the regression equation c. most of the variation in y is unexplained by the regression equation d. the model provides a poor fit e. most of the variation in y is explained by the regression equation and the model provides a poor fit ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 95. Which of the following statements regarding multicollinearity is not true? a. Multicollinearity exists in virtually all multiple regression models. b. One of the signs of multicollinearity is that the value of is large, indicating a good fit, but the individual ttests are nonsignificant. c. Multicollinearity is a condition that exists when the independent variables are highly correlated with

the dependent variable. d. Multicollinearity does not affect the F-test of the analysis of variance. e. All of these.

Chapter 13 - Multiple Linear Regression Analysis ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/12/2019 5:44 AM 96. The adjusted coefficient of determination is adjusted for the: a. number of regression parameters including the y-intercept b. number of dependent variables and the sample size c. number of independent variables and the sample size d. F statistic and the significance level e. number of independent variables and the significance level ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/16/2019 5:40 AM 97. In a multiple regression model, the standard deviation of the error variable is assumed to be: a. constant for all values of the independent variables b. constant for all values of the dependent variable c. 1.0 d. 0 e. Not enough information is given to answer this question. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 98. In multiple regression analysis, the ratio MSR/MSE yields the: a. coefficient of determination b. F-test statistic for testing the validity of the regression equation c. t-test statistic for testing each individual regression coefficient d. adjusted coefficient of determination e. F-test statistic for testing the validity of the regression equation and t-test statistic for testing each

individual regression coefficient ANSWER:

POINTS:

Chapter 13 - Multiple Linear Regression Analysis QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/12/2019 5:46 AM 99. In a multiple regression analysis involving 25 observations and 6 independent variables, the coefficient of

determination is calculated as:

. Then, the value of the F-test statistic for this model is:

a. 5.82 b. 6.15 c. 2.32 d. 34.94 e. none of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/12/2019 6:22 AM 100. In order to test the validity of a multiple regression model involving 5 independent variables and 30

observations, the numerator and denominator degrees of freedom for the critical value of F are: a. 5 and 30, respectively b. 6 and 29, respectively c. 5 and 24, respectively d. 6 and 25, respectively e. 4 and 32, respectively ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/12/2019 6:24 AM 101. In multiple regression models, the values of the random error are assumed to be: a. autocorrelated b. dependent of each other c. independent of each other d. always positive e. independent of each other and always positive ANSWER: c POINTS:

Chapter 13 - Multiple Linear Regression Analysis QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/11/2019 9:32 AM 102. A multiple regression model involves 5 independent variables and a sample of 10 data points. If we want to

test the validity of the model at the 5% significance level, the critical value is: a. 6.26 b. 3.33 c. 9.36 d. 4.24 e. 2.58 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 103. To test the validity of a multiple regression model, we test the null hypothesis that the regression

coefficients are all zero by applying: a. the t-test b. the z-test c. the F-test d. the chi-square test e. all of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 104. To test the validity of a multiple regression model involving two independent variables, the null hypothesis

is that: a. b. c. d. e.

Chapter 13 - Multiple Linear Regression Analysis ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 105. A multiple regression model has the form a. change in b. change in c. change in d. change in e. change in

. The coefficient

is interpreted as the:

per unit change in per unit change in , holding constant per unit change in , when and values are correlated per unit change in , holding constant per unit change in

ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/16/2019 6:01 AM 106. In a multiple regression analysis involving 10 observations and 3 independent variables, Total SS = 900

and MSE = 45. Then, the adjusted coefficient of determination is: a. 70% b. 65% c. 45% d. 55% e. 60% ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/12/2019 6:57 AM 107. The coefficient of determination ranges from: a. 1.0 to b. 0.0 to 1.0 c. . 1.0 to 0 d. 1.0 to k, where k is the number of independent variables in the model

Chapter 13 - Multiple Linear Regression Analysis e. 1.0 to n, where n is the number of observations in the dependent variable ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/16/2019 6:05 AM 108. In testing the validity of a multiple regression model involving 10 independent variables and 100

observations, the numerator and denominator degrees of freedom for the critical value of F will be: a. 9 and 90, respectively b. 10 and 100, respectively c. 9 and 10, respectively d. 10 and 89, respectively e. 8 and 16, respectively ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/12/2019 6:59 AM 109. In multiple regression analysis involving 10 independent variables and 100 observations, the critical value

of t for testing individual coefficients in the model will have: a. 100 degrees of freedom b. 10 degrees of freedom c. 99 degrees of freedom d. 89 degrees of freedom e. 9 degrees of freedom ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 110. A multiple regression equation includes 5 independent variables, and the coefficient of determination is

0.81. The percentage of the variation in y that is explained by the regression equation is: a. 81% b. 90% c. 86% d. 85%

Chapter 13 - Multiple Linear Regression Analysis e. about 16% ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 111. In a multiple regression model, which of the following statements is false? a. The coefficient of determination will be equal to the square of the F statistic. b. For given values of

, the confidence interval will always be wider than the prediction interval. c. Adding more independent variables will decrease the value of the coefficient of determination. d. All of the above. e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/16/2019 6:14 AM 112. Which of the following statements is true? a. The

value will tend to be smaller than the adjusted value when insignificant independent variables are included in the model. b. The y-intercept will usually be negative in a multiple regression model when the partial regression coefficients are positive. c. If the confidence interval estimate for the partial regression coefficient, based on the sample information, crosses over zero, then the true population partial regression coefficient could be zero. d. The x-intercept will usually be positive in a multiple regression model when the partial regression coefficients are negative. e. None of these. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/12/2019 7:43 AM 113. Which of the following best described the model a. Third-order polynomial model.

Chapter 13 - Multiple Linear Regression Analysis b. Second-order polynomial model. c. First-order polynomial model since there is only one independent variable x. d.

Quadratic model since the term

will often be dropped out the model based on sample

information. e. First-order polynomial model since there is only one dependent variable y. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/16/2019 6:16 AM 114. In a multiple regression model, if the regression assumptions are valid, which of the following should be

evident? a. The plot of residuals versus fit shows k vertical lines of residuals, where k is the number of

independent variables. b. The normal probability plot of residuals is closely resembled a straight line, sloping upward to the right. c. The normal probability plot of residuals shows the curved pattern. d. All of the above. e. None of these. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/16/2019 6:27 AM 115. Which of the following methods is used to assess whether the regression model meets the assumption of

having normally distributed residuals? a. Develop a dotplot of the residuals. b. Develop a bar chart of the residuals. c. Develop a normal probability plot of the population means. d. Both develop a normal probability plot of the residuals and develop a histogram of the residuals. e. Neither develop a normal probability plot of the residuals nor develop a histogram of the residuals. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/16/2019 6:35 AM

Chapter 13 - Multiple Linear Regression Analysis

116. The first-order model

attempts to explain average air temperatures in degrees

Fahrenheit for a particular day as a function of distance from the coast ( hundreds of feet). Interpret the parameters .

in miles), and altitude (

(Do not round the coefficients.) = Interpret

= Interpret

ANSWER:

60; 60 is the average temperature at the coast (x1 = 0) at sea level (x2 = 0).; 0.25; At a fixed altitude, the temperature increases on average by 0.25 degrees Fahrenheit as the distance from the coast increases by one mile.; -.40; -0.40 is the change in y for a one unit change in x2 when x1 is held constant. It tells us that at a given distance from the coast, temperature decreases on average by 0.40 degrees Fahrenheit as altitude increases by one hundred feet above sea level.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/16/2019 7:06 AM 117. An automobile manufacturer would like to know the gas mileage of a car (y in miles per gallon) based on

four predictor variables: = horsepower (ft-lb), = torque (ft-lb), = displacement (cubic inches), and weight (lbs). Suppose the following equation does indeed describe the true relationship.

Chapter 13 - Multiple Linear Regression Analysis

What is the gas mileage for a car with 160 ft-lbs of horsepower, 250 ft-lbs of torque, 350 cubic inches of displacement, and weighs 3900 pounds? Do not round your answer. miles/gallon What is the gas mileage for a car with 210 ft-lbs of horsepower, 330 ft-lbs of torque, 440 cubic inches of displacement, and weighs 4210 pounds? Do not round your answer. miles/gallon How would you interpret the value of

How would you interpret the value of

ANSWER:

23.05; 21.752; β1 = 0.0145 is the change in y for a one unit change in x1 when all other independent variables are held constant. This means that when the horsepower increases by 1 ft-lb, the gas mileage will increase on average by 0.0145 miles per gallon if all other independent variables are held constant.; β 2 = 0.054 is the change in y for a one unit change in x 2 when all other independent variables are held constant. This means that when the torque increases by 1 ft-lb, the gas mileage will increase on average by 0.054 miles per gallon if all other independent variables are held constant. β 3 = -0.066 is the change in y for a one unit change in x 3 when all other independent variables are held constant. This means that when the displacement increases by 1 cubic inch, the gas mileage will decrease on average by 0.066 miles per gallon if all other independent variables are held constant. β 4 = -0.0013 is the change in y for a one unit change in x 4 when all other independent variables are held constant. This means that when the weight increases by 1 pound, the gas mileage will decrease on average by 0.0013 miles per gallon if all other independent variables are held constant.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic

Chapter 13 - Multiple Linear Regression Analysis DATE CREATED: DATE MODIFIED:

2/4/2019 9:44 AM 4/16/2019 7:01 AM

118. Is personal spending linearly related to orders for durable goods and personal income? A recent study

reported the amount of personal spending (in trillions of dollars), the amount spent on durable goods (in billions of dollars), and personal income (in trillions of dollars). A statistical package was used to fit a linear regression model, producing the output below.

Write the model that was fit. Include the estimates of the parameters. Do not round the coefficients. =

Predict the level of personal spending when amount spent on durable goods is 130 and personal income is at 5.10. Do not round your answer.

Use the computer output shown above to calculate 95% confidence intervals for the intercept and the partial regression coefficients. What is the confidence interval for CI =

Enter (n1, n2)

What is the confidence interval for CI =

? Round the limits to four decimal places.

Enter (n1, n2)

What is the confidence interval for CI =

? Round the limits to four decimal places.

Enter (n1, n2)

Based on your confidence intervals, does the amount spent on durable goods have any predictive power beyond that provided by the other independent variables for determining personal spending?

Based on your confidence intervals, does personal income have any predictive power beyond that provided by

Chapter 13 - Multiple Linear Regression Analysis

the other independent variables for determining personal spending?

Use the computer output shown above to test the hypotheses: level. What is your conclusion?

at the 5% significance

the null hypothesis. We conclude spending on durable goods predict personal spending.

predictive power over and above personal income to

Use the computer output shown above to test the hypotheses level. What is your conclusion?

at the 5% significance

Conclude: the null hypothesis. Personal income ANSWER:

predictive power beyond that provided by the other independent variable. -.6023; -.0013; .958; 4.1145; (-1.4678, .2632); (-0.0049, 0.0023); (0.7266, 1.1894); No.; Yes.; Fail to reject; has no; Reject; does have

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/16/2019 7:05 AM 119. A publisher is studying the effectiveness of advertising to sell a woman's magazine. She wishes to

investigate the relationship between the number of magazines sold (10,000's), the "reach" (proportion of the population who see at least one advertisement for the magazine), and the average income of the target market ($1,000's). The publisher suspects people at certain income levels might be more susceptible to this advertising campaign than others. Preliminary studies show there is no evidence of a quadratic relationship between sales and either of the other two variables. Use the output below to answer the questions.

Chapter 13 - Multiple Linear Regression Analysis

Is there an interaction effect? Test at the 5% significance level. One may conclude that there interaction between the "reach" (proportion of the population who see at least one advertisement for the magazine), and the average income of the target market. Develop 95% confidence intervals for the intercept and the partial regression coefficients. The confidence interval for CI =

Enter (n1, n2). Round the limits to four decimal places.

The confidence interval for C I=

is:

Enter(n1, n2). Round the limits to four decimal places.

The confidence interval for CI =

is:

Enter(n1, n2). Round the limits to two decimal places.

The confidence interval for CI =

is:

Enter(n1, n2). Round the limits to four decimal places.

Explain how to use the 95% confidence interval you constructed for We ANSWER: POINTS: QUESTION TYPE:

to test the hypotheses made earlier.

the null hypothesis at the 5% significance level. is no; (1.5813, 4.6187); (7,135.27, 13,546.73); (0.1877, 1.5523); (-0.5037, 7.0237); fail to reject 1 Subjective Short Answer

Chapter 13 - Multiple Linear Regression Analysis HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/12/2019 8:42 AM 120. Suppose you have a choice of three multiple regression models. Listed below are the independent variables

(predictors) and the values of

and adjusted

for each model.

Which model would you choose as the most appropriate to use?

ANSWER:

Choose the second model.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/12/2019 8:11 AM 121. Consider the following partial output generated using Minitab:

Which, if any, of the terms should be removed from the model first?

Justify your answer. (Use a significance level of 0.05.) It has

p-value.

Chapter 13 - Multiple Linear Regression Analysis

Which of the predictors makes the most significant contribution in predicting the dependent variable y?

Justify your answer. It has

p-value.

What is the coefficient of determination? =

. Use the % sign.

Interpret the value.

ANSWER:

x3; the largest; x1; the smallest; 95.2%; This means that 95.2% of the total variability in the dependent variable y can be explained by the current model. Thus, the model is doing a good job.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/17/2019 4:22 AM 122. A chemist was interested in examining the effects of three chemicals on chemical process yield. Let

,i= 1, 2, 3, represent the effects of the three chemicals, respectively and y be the process yield. The following output was generated using statistical software.

Find the least squares regression equation. Do not round the coefficients. =

Chapter 13 - Multiple Linear Regression Analysis

Test the usefulness of the model at the 0.05 level of significance. The null and alternative hypotheses of interest are:

vs.

Test statistic: F=

. Do not round your answer.

Rejection region: Reject H0 if F >

. Round your answer to two decimal places.

Conclude:

of the predictor variables (one of the three chemicals) is contributing significant information for the prediction of the chemical process yield. Which variable, if any, should be removed from the model if a 0.05 level of significance is desired?

ANSWER:

225.19; 12.725; -39.45; -33.48; 32.19; 5.41; Reject the null hypothesis; At least one; x2

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/17/2019 3:40 AM 123. The sequential sums of squares represent the conditional contribution of each of the predictor variables

given the variables already in the model. Use the following partial output generated using Minitab to determine which predictor variable accounts for the largest proportion of the total variation explained by the regression model.

Chapter 13 - Multiple Linear Regression Analysis

Which variable accounts for the largest proportion?

What is the proportion accounted by the selected variable? Round your answer to one decimal place. Use the % sign. ANSWER:

x1; 87.3%

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/17/2019 3:36 AM 124. Suppose that you fit the model

to 15 data points and found F equal to

52.36. Do the data provide sufficient evidence to indicate that the model contributes information for the prediction of y? Test using a 5% level of significance.

Use the value of F to calculate

. Round your answer to four decimal places.

Interpret its value.

ANSWER:

Yes.; .9346; The above value means that the total sum of squares of deviations of the y-values about their mean has been reduced by 93.46% by using the linear model to predict y.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/12/2019 9:11 AM 125. The computer output for a multiple regression analysis including 15 observations and three predictor

variables, x1, x2, and x3 provides the following information:

Chapter 13 - Multiple Linear Regression Analysis

Which, if any, of the independent variables level of significance

and

contribute information for the prediction of y? Use the

(Round your answers to three decimal places if necessary.) Compute the t-statistic for each predictor variable and decide whether or not it is significant: =

significant.

Give the least-squares prediction equation. =

What is the practical interpretation of the parameter

ANSWER:

. ?

2.978; is; 4.074; is; 2.3; is; 1.09; 1.34; 2.77; .46; β1 represents the change in y for a one unit change in x1 when x2 and x3 and are held constant.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/17/2019 3:47 AM 126. An actuary wanted to develop a model to predict how long individuals will live. After consulting a number

of physicians, she collected the age at death (y), the average number of hours of exercise per week (x1), the cholesterol level (x2), and the number of points that the individual's blood pressure exceeded the recommended value (x3). A random sample of 40 individuals was selected. The computer output of the multiple regression model is shown below.

Chapter 13 - Multiple Linear Regression Analysis

Is there enough evidence at the 10% significance level to infer that the model is useful in predicting the length of life? enough evidence at the 10% significance level to infer that the model is useful in predicting the length of life. Is there enough evidence at the 1% significance level to infer that the average number of hours of exercise per week and the age at death are linearly related? What is the test statistic? t=

. Do not round your answer.

Conclude: . There enough evidence at the 1% significance level to infer that the average number of hours of exercise per week and the age at death are linearly related. Is there enough evidence at the 5% significance level to infer that the cholesterol level and the age at death are negatively linearly related? What is the test statistic? t=

. Do not round your answer.

Chapter 13 - Multiple Linear Regression Analysis

Conclude: . There enough evidence at the 5% significance level to infer that the cholesterol level and the age at death are negatively linearly related. Is there sufficient evidence at the 5% significance level to infer that the number of points that the individual's blood pressure exceeded the recommended value and the age at death are negatively linearly related? What is the test statistic? t=

. Do not round your answer.

Conclude: . There sufficient evidence at the 5% significance level to infer that the number of points that the individual's blood pressure exceeded the recommended value and the age at death are negatively linearly related. What is the coefficient of determination? =

. Use the % sign. Do not round your answer.

Explain:

ANSWER:

Yes, there is; 4.068; Reject; is; -1.909; Do not reject; is not; -1.143; Do not reject; is not; 22.5%; This means that 22.5% of the variation in the age at death is explained by the three variables: the average number of hours of exercise per week, the cholesterol level, and the number of points that the individual’s blood pressure exceeded the recommended value, while 77.5% of the variation remains unexplained.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/17/2019 4:19 AM 127. A statistician wanted to determine if the demographic variables of age, education, and income influence the

number of hours of television watched per week. A random sample of 25 adults was selected to estimate the multiple regression model:

Chapter 13 - Multiple Linear Regression Analysis

where y is the number of hours of television watched last week, x1 is the age (in years), x2 is the number of years of education, and x3 is income (in $1,000). The computer output is shown below.

Test the overall validity of the model at the 5% significance level. What is the test statistic? F=

. Do not round your answer.

Conclude that the model

valid at the 5% level.

Is there sufficient evidence at the 1% significance level to indicate that hours of television watched and age are linearly related? What is test statistic? t=

. Do not round your answer.

Conclude that there sufficient evidence at the 1% significance level to indicate that hours of television watched and age are linearly related.

Chapter 13 - Multiple Linear Regression Analysis

Is there sufficient evidence at the 1% significance level to indicate that hours of television watched and education are negatively linearly related? What is the test statistic? t=

. Do not round your answer.

Conclude that there sufficient evidence at the 1% significance level to indicate that hours of television watched and education are negatively linearly related. What is the coefficient of determination? =

. Do not round your answer.

Interpret this value for

Interpret

ANSWER:

3.73; Reject; is; 2.158; Do not reject; is not; -2.231; Do not reject; is not; 34.8%; This means that 34.8% of the variation in the number of hours of television watched per week is explained by the three variables: age, number of years of education, and income, while 65.2% remains unexplained.; This tells us that for each additional year of age, the number of hours of television watched per week on average increases by 0.41 (assuming that the other independent variables in the model are held constant).; This tells us that for each additional year of education, the number of hours of television watched per week on average decreases by 0.29 (assuming that the other independent variables in the model are held constant).; This tells us that for each additional income of $1000, the number of hours of television watched per week on average decreases by 0.12 (assuming that the other independent variables in the model are held constant).

POINTS: QUESTION TYPE: HAS VARIABLES:

1 Subjective Short Answer False

Chapter 13 - Multiple Linear Regression Analysis STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/17/2019 3:59 AM 128. Use the following partial output and residual plot generated using statistical software to determine whether

there are any potential outliers in this data.

What are the potential outliers? Enter the observation numbers 1-9, separated by commas if there is more than one. Explain:

ANSWER:

5; Based on the output and the plot, it would appear that observation #5 is close to being a suspect outlier since it has a standardized residual close to 2. POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic

Chapter 13 - Multiple Linear Regression Analysis DATE CREATED: DATE MODIFIED:

2/4/2019 9:44 AM 2/4/2019 9:44 AM

129. Americans are very vocal about their attempts to improve personal well-being by "eating right and

exercising more." One desirable dietary change is to reduce the intake of red meat and to substitute poultry or fish. A medical team from Florida tracked beef and chicken consumption (in annual pounds per person) and found the consumption of beef declining and the consumption of chicken increasing from 1970 through the year 2000. A summary of their data is shown in the table. Year 1970 1975 1980 1985 1990 1995 2000

Beef 87 91 78 78 70 69 62

Chicken 39 38 49 49 64 76 81

Consider fitting the following model, which allows for simultaneously fitting two simple linear regression lines: E(y) = β0+β1x1 + β2x2+ β3x1x2 where

Minitab printouts using this model are provided here. Regression Analysis

The regression equation is Y = -3020.2 + 4897.3 X1 + 1.55 X2 - 2.4571 X1X2 Predictor Constant x1 X2 X1X2 S = 4.167

Coef -3020.2 4897.3 1.5500 -2.4571

stDev 312.6 442.1 0.1575 0.2227

R - Sq = 95.4%

Analysis of Variance Source DF 3 Regression Residual Error 10 Total 13 Source X1 X2 X1X2

SS 3637.9 173.6 3811.5

T -9.66 11.08 9.84 -11.03

R - Sq (adj) = 94.1% MS 1212.6 17.4

DF 1 1 1

Predicted Value Fit StDev Fit 56.29 3.52

P 0.00 0.00 0.00 0.00

F 69.83

P 0.000

Seq SS 1380.1 144.6 2113.1 95.0% CI (48.44, 64.13)

95.0% PI (44.13, 68.44)

Chapter 13 - Multiple Linear Regression Analysis

How well does the model fit? Use any relevant statistics and diagnostic tools from the printout to answer this question. The level of significance is 0.05. Test statistic:

. Do not round your answer.

Chapter 13 - Multiple Linear Regression Analysis

p-value:

_. Do not round your answer.

Conclude:

The model

significant information for the prediction of y.

Write the equations of the two straight lines that describe the trend in consumption over a period of 30 years for beef and for chicken. Do not round the coefficients. For chicken:

For beef:

Use the prediction equation to find a point estimate of the average per-person beef consumption in 2007.

. Round your answer to two decimal places.

Compare this value with the value labeled "Fit" in the printout.

Use the printout to find a 95% confidence interval for the average per-person beef consumption in 2007. The confidence interval is:

CI =

Enter (n1, n2). Do not round the limits.

What is the 95% prediction interval for the per-person beef consumption in 2007? The 95% prediction interval is:

PI =

Enter (n1, n2). Do not round the limits.

Is there any problem with the validity of the 95% confidence level for these intervals?

Chapter 13 - Multiple Linear Regression Analysis ANSWER:

69.83; 0; contributes; -3020.2; 1.55; 1877.1; -.9071; 56.55; To within rounding error, this is the value marked “Fit” in the computer printout.; (48.44,64.13); (44.13, 68.44); Since you are predicting outside of the experimental unit, there is a danger of inaccurate predictions!

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/17/2019 4:33 AM 130. An engineer was investigating the relationship between the thrust of an experimental rocket (y), the percent

composition of a secret chemical in the fuel (x1) and the internal temperature of a chamber of the rocket (x2). The engineer starts by fitting a quadratic model, but he believes that the full quadratic model (contained four variables) is too complex and can be reduced by only including the linear terms and the interaction term. The engineer obtained a random sample of 66 measurements and computed the SSE for both the complete model and the reduced model. The values were 1477.8 and 1678.8, respectively. Perform the appropriate test of hypothesis to determine whether the reduced model is adequate for the engineer's use. Use = 0.05. (Round your answers to two decimal places.) Test statistic: F= What is the critical value of F?

Conclude: . There evidence to indicate that at least one of the two quadratic variables is contributing significant information for predicting y. ANSWER: 4.15; 3.15; Reject; is POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/17/2019 4:39 AM 131. A chemist was interested in examining the effects of four chemicals on a chemical process yield. Let

,i= 1, 2, 3, 4, represent the effects of the four chemicals, respectively and y be the process yield. The chemist's first

Chapter 13 - Multiple Linear Regression Analysis

instinct was to include each of the chemicals in the equation in a linear fashion. After the initial analysis, the chemist decided to remove chemicals 2 and 3 from the model. Complete model:

Reduced model:

Use the statistical software output above to test whether the reduced model is adequate at the 0.05 level of significance. (Round your answers to three decimal places.) Test Statistic: F= Reject Region: Reject

if F >

Conclusion: There The reduced model

evidence to indicate that at least one of adequate.

is not 0.

Chapter 13 - Multiple Linear Regression Analysis ANSWER:

1.214; 6.944; Do not reject the null hypothesis; is no; is

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/17/2019 4:46 AM 132. The two largest values in a correlation matrix are the 0.89 correlation between y and x3 the 0.83 correlation

between y and x7. During a stepwise regression analysis x3 is the first independent variable brought into the equation. Will x7 necessarily be next?

Explain.

ANSWER:

No; We do not know about the correlation between x3 and x7 , so we cannot determine whether x7 will explain the greatest amount of the remaining variation in y.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/17/2019 5:59 AM 133. A publisher of college textbooks conducted a study to relate profit per text y to cost of sales x over a 6-year

period when its sales force (and sales costs) were growing rapidly. These inflation-adjusted data (in thousands of dollars) were collected:

Expecting profit per book to rise and then plateau, the publisher fitted the model What conclusions can you draw from the accompanying residual plots?

to the data.

Chapter 13 - Multiple Linear Regression Analysis

ANSWER:

There are no obvious violations in the assumptions based on the patterns shown in the diagnostic plots.

POINTS: 1 QUESTION TYPE: Essay HAS VARIABLES: False STUDENT ENTRY MODE: Basic

Chapter 13 - Multiple Linear Regression Analysis DATE CREATED: DATE MODIFIED:

2/4/2019 9:44 AM 2/4/2019 9:44 AM

134. What is stepwise regression, and when is it desirable to make use of this multiple regression technique? ANSWER: Stepwise regression is a multiple regression estimation technique whereby

independent variables are added to the regression equation one at a time. The first x variable to enter the regression is the one that explains the greatest amount of variation in y. The second variable to enter is the one that explains the greatest amount of the remaining variation. The use of stepwise regression can reduce the possibility for multicollinearity since it is unlikely that two highly correlated x variables will be included in a multiple regression that is estimated using the stepwise technique. This technique is useful when there are many independent variables. POINTS: 1 QUESTION TYPE: Essay HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/15/2019 6:50 AM 135. In general, on what basis are independent variables selected for entry into the equation during stepwise

regression? ANSWER:

Independent variables are selected for entry into the equation during stepwise regression based upon the amount of the remaining variation in y (the variation that has not already been explained by included variables) that a candidate variable can explain.

POINTS: 1 QUESTION TYPE: Essay HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/15/2019 6:51 AM 136. Qualitative predictor variables are entered into a regression model through dummy variables. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 137. Quantitative predictor variables are entered into a regression model through indicator variables. a. True

Chapter 13 - Multiple Linear Regression Analysis b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 138. The t-distribution with df = n - 2 is used for testing a specific set of regression coefficients, e.g.,

. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 139. Plots of the residuals versus fit or versus the individual independent variables

often indicate departures from the assumptions required for an analysis of variance, and they also may suggest changes in the underlying model. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/17/2019 4:53 AM 140. Stepwise regression analysis is a procedure that is implemented by a computer and is available in most

statistical packages. It is mainly used to determine which of a large number of independent variables should be included in the model. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/11/2019 10:10 AM 141. A dummy or indicator variable is a dependent variable whose values are either 0.0 or 1.0.

Chapter 13 - Multiple Linear Regression Analysis a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 142. In order to incorporate qualitative variables into a regression model, one or more dummy variables are

needed. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 143. In order to incorporate the marital status variable into a multiple regression model, there are four possible

categories for this variable: married, single, divorced, or widow. Based on this information, four indicator variables will need to be created (one for each category) and incorporated into the regression model. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/15/2019 7:09 AM 144. Three qualitative variables need to be incorporated into a regression model. The first variable has 5

possible categories, the second one has 3 possible categories, and the third one has 2 possible categories. Based on this information, ten dummy variables need to be included in the regression model. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM

Chapter 13 - Multiple Linear Regression Analysis 145. In a multiple regression analysis, the regression equation

is obtained. The variable is quantitative variable, and the variable is a dummy variable with values 0 and 1. Given this information, we can interpret the slope coefficient (-3) on variable as follows: Holding constant, if the value of is changed from 0 to 1, the average value of y will decrease by 3 units. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/15/2019 7:14 AM 146. If you wish to develop a multiple regression model that includes a qualitative variable "education status", in

which the following categories exist: no degree, high school diploma, junior college degree, bachelor degree, and graduate degree, you need to code the categories as 1, 2, 3, 4, and 5. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/15/2019 7:16 AM 147. Stepwise regression is a statistical technique that is always implemented when developing a regression

model to fit a nonlinear relationship between the dependent and potential independent variables. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 148. In constructing a multiple regression model with two independent variables

and it was known that the correlation between and y is .75, and the correlation between and y is .55. The correlation between x1 and x2 is .95. Based on this information, during the stepwise regression analysis, both x1 and x2 should be brought into the equation. a. True b. False ANSWER:

False

Chapter 13 - Multiple Linear Regression Analysis POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/17/2019 6:04 AM 149. If stepwise procedure is used, a variable selected at an earlier step can be removed from the model if, in the

presence of other variables, it no longer contributes significantly to explaining the variation in the dependent variable y. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 150. If a stepwise regression procedure is used to enter, one at a time, three variables into a regression model,

the resulting regression equation may differ from the regression equation that occurs when all three variables are entered at one step. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 151. Stepwise regression analysis is most useful when it is anticipated that there are curvilinear relationships

between the dependent variable and the potential independent variables. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 152. The stepwise regression analysis is best used as a preliminary tool for identifying which of a large number

of variables should be considered in the model. a. True b. False

Chapter 13 - Multiple Linear Regression Analysis ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 153. Stepwise regression is especially useful when there are: a. many independent variables b. few independent variables c. many dependent variables d. few dependent variables e. two independent variables ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/15/2019 7:29 AM 154. Stepwise regression is an iterative procedure that: a. always adds four independent variables at a time b. deletes one dependent variable at a time c. adds one dependent variable at a time d. either adds one independent variable at a time or deletes one independent variable at a time e. both adds one independent variable at a time and deletes one independent variable at a time ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/17/2019 5:02 AM 155. In a stepwise regression procedure, if two independent variables are highly correlated, then: a. both variables will enter the equation b. only one variable will enter the equation c. neither variable will enter the equation d. the regression is equal to zero e. Not enough information is given to answer this question. ANSWER: b POINTS: 1

Chapter 13 - Multiple Linear Regression Analysis QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/15/2019 7:39 AM 156. In binary logistic regression, if p is the probability of the occurrence of the event of interest, the odds ratio

is given by: a. p b. 1-p c. d. e. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/17/2019 5:12 AM 157. In multiple regression analysis, which procedure permits variables to enter and leave the model at different

stages of its development? a. forward selection b. residual analysis c. backward elimination d. stepwise regression e. chi-square test ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 158. If you wish to develop a regression model in which the High School Class standing is a qualitative variable

with 4 possible levels of response, then you will need to include how many dummy variables? a. 6 b. 5 c. 4 d. 3

Chapter 13 - Multiple Linear Regression Analysis e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 159. Which of the following statements is true? a. A regression model can contain interactions of the dummy variables with other variables that appear

in the model. b. If a qualitative variable has m categories, you should use m - 1 dummy variables to incorporate the qualitative variable into a regression model. c. Dummy variables are used to incorporate qualitative variables into a regression model. d. All of the above. e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/17/2019 5:19 AM 160. Assume you are considering including two additional qualitative variables into a regression model. The

first variable has 4 categories, and the second variable has 4 categories as well. Given this information, how many indicator variables will be incorporated into the model? a. 8 b. 7 c. 6 d. 5 e. 4 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 161. Which of the following statements is correct? a. The number of dummy variables that must be added to a regression model is one less than the

number of categories for a qualitative independent variable. b. A dummy variable is incorporated into a regression model if the dependent variable is qualitative. c. Including a dummy variable into a regression model will simplify the regression results and help

Chapter 13 - Multiple Linear Regression Analysis

people to interpret the meaning of the regression parameters. d. The number of dummy variables that must be added to a regression model is one more than the number of categories for a qualitative independent variable. e. All of these. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 162. Which of the following is an advantage of using stepwise regression compared to just entering all the

independent variables at one time? a. There are no advantages of using stepwise regression over entering all the variables at one time. b. Stepwise regression allows us to observe the effects of multicollinearity more early than when all

variables are entered at one time. c. Stepwise regression allows us to detect curvature in the data. d. All of the above. e. None of these. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/17/2019 6:10 AM 163. Multicollinearity is a situation in which two or more of the independent variables are highly correlated with

each other. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 164. If a multiple regression model includes 10 or more predictor variables, it is almost certain that changes in

the predictor variables cause changes in the response variable y. a. True b. False ANSWER: POINTS:

False 1

Chapter 13 - Multiple Linear Regression Analysis QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 165. Multicollinearity is present if the response variable is linearly related to one of the explanatory variables. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/15/2019 8:17 AM 166. Multicollinearity is present when there is a high degree of correlation between the dependent variable and

all the independent variables included in the model. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 167. One of the consequences of multicollinearity in multiple regression is inflated standard errors in some or all

of the estimated slope coefficients. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 168. Multicollinearity will result in excessively low standard errors of the parameter estimates reported in the

regression output. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False

Chapter 13 - Multiple Linear Regression Analysis HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 169. When two or more of the predictor variables are highly correlated with one another, adding or deleting a

predictor variable may cause significant changes in the values of the other regression coefficients. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 170. When multicollinearity is present, the estimated regression coefficients will have large standard error,

causing imprecision in confidence and prediction intervals. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 171. In regression analysis, multicollinearity refers to: a. the response variables being highly correlated with one another b. the predictor variables being highly correlated with one another c. the response variables being not correlated with one another d. the predictor variables being not correlated with one another e. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/15/2019 8:29 AM 172. When the independent variables are correlated with one another in a multiple regression analysis, this

condition is called: a. normality b. variability

Chapter 13 - Multiple Linear Regression Analysis c. multicollinearity d. causality e. none of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/15/2019 8:38 AM 173. Typical symptoms of the presence of multicollinearity include: a. the estimated regression coefficients to vary substantially from sample to sample; this fact raises their

standard errors b. the estimated regression coefficients change greatly in value as independent variables are dropped from or added to the regression equation c. the signs of the estimated regression coefficients are nonsensical; they are negative when common sense suggests positive signs and vice versa d. all of the above and more e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/17/2019 6:12 AM 174. Which of the following statements regarding multicollinearity is true? a. When multicollinearity is present in a regression problem, it means that changes in the independent

variable cause changes in the dependent variable. b. When multicollinearity is present in a regression problem, it can effects that the estimated regression coefficients will have large standard errors. c. When multicollinearity is present in a regression problem, the independent variables are highly correlated with the dependent variable. d. Multicollinearity affects the F-test of the analysis of variance. e. All of these ANSWER:

POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/17/2019 5:33 AM

Chapter 13 - Multiple Linear Regression Analysis 175. To check for violation of the regression assumptions, you should: a. Use the t-test. b. Use the analysis of variance F-test. c. Use computer-generated residual plots. d. All of the above e. None of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/17/2019 5:53 AM 176. If multicollinearity exists among the independent variables included in a multiple regression model, then: a. multiple coefficient of determination will assume a value close to -1 b. standard errors of the regression coefficients for the correlated independent variables will decrease c. multiple coefficient of determination will assume a value close to zero d. standard errors of the regression coefficients for the correlated independent variables will increase e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/15/2019 8:50 AM 177. In multiple regression analysis, which of the following is a clue that multicollinearity is present? a. The value of is large, indicting a good fit, but the individual t - tests are nonsignificant. b. The signs of the regression coefficients are contrary to what we would intuitively expect the

contributions of those variables would be. c. A matrix of correlations, generated by a computer, shows which predictor variables are highly correlated with each other and with the response variable y. d. All of the above. e. None of these. ANSWER:

POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/15/2019 8:51 AM

Chapter 13 - Multiple Linear Regression Analysis 178. Three predictor variables are being considered for use in a linear regression model.

Given the correlation matrix above, does it appear that multicollinearity could be a problem?

Explain.

ANSWER:

Yes; It appears that multicollinearity could be a problem because x3 is highly correlated with both x1 and x2. POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/17/2019 5:55 AM

179. Discuss some of the signals for the presence of multicollinearity. ANSWER: There are several clues to the presence of multicollinearity: a. An independent

variable known to be an important predictor ends up having a partial regression coefficient that is not significant. b. A partial regression coefficient exhibits the wrong sign. c. When an independent variable is added or deleted, the partial regression coefficients for the other variables change dramatically. A more practical way to identify multicollinearity is through the examination of a correlation matrix, which is a matrix that shows the correlation of each variable with each of the other variables. A high correlation between two independent variables is an indication of multicollinearity. POINTS: 1 QUESTION TYPE: Essay HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 180. Discuss briefly what is meant by multicollinearity. ANSWER: Multicollinearity is a condition that exists when two or more of the independent

variables are highly correlated with each other. POINTS:

Chapter 13 - Multiple Linear Regression Analysis QUESTION TYPE: Essay HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 4/15/2019 8:55 AM 181. What is the effect of multicollinearity on the estimated regression coefficients? ANSWER: The adverse effect of multicollinearity is that the estimated regression coefficients

of the independent variables that are correlated tend to have large sampling errors. POINTS: 1 QUESTION TYPE: Essay HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:44 AM DATE MODIFIED: 2/4/2019 9:44 AM 182. Consider the situation. In late spring, the cafe entered into an agreement with a new ice cream supplier. Two months later, the cafe owner noticed that the sales of ice cream had increased. Can the owner conclude that the change of ice cream supplier led to an increase of ice cream sales? a. Yes, he/she certainly can. b. Two months is a too short period, the owner cannot conduct a correct statistical analysis. c. The owner cannot say anything about the causal relationship of these events because there are other factors, such as a seasonal increase in ice cream sales. d. The increase in ice cream sales and the appearance of a new supplier cannot be related. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 6:29 AM DATE MODIFIED: 2/6/2019 6:33 AM 183. The bank manager wants to develop a model that would help him identify bank customers who are ready to take a consumer loan. The manager believes that there is a relationship between monthly salary, age, availability of a credit card, and readiness to take a consumer loan. In the table below, there are data of 25 bank consumers. Customer 1 2 3 4 5 6 7

Montly salary, in $1000 1.59 2.89 5.33 5.63 2.92 5.74 3.07

Credit card

Age

Consumer loan

1 1 1 1 1 1 1

22 29 32 34 34 36 36

1 1 0 1 0 0 0

Chapter 13 - Multiple Linear Regression Analysis 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

3.07 6.40 3.62 4.13 6.01 5.33 6.43 5.07 5.03 3.17 4.13 4.17 4.18 4.68 2.76 3.12 2.10 1.59

1 1 0 0 1 0 1 1 0 1 0 0 0 1 0 0 0 1

38 39 39 40 43 45 46 48 51 52 52 53 62 64 65 70 71 22

0 0 1 1 0 0 0 0 0 1 1 0 0 0 0 0 0 1

Using this data and a technology application (like Minitab), build a binary logistic model of this study. The form of the model is

where MS is mountly salary, CC is credit card, and A is age. Enter the coefficients rounded to three decimal places.

ANSWER: 8.779; –0.547; –2.155; –0.143 POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 6:57 AM DATE MODIFIED: 2/6/2019 8:36 AM 184. It is known that the flu vaccine helps to avoid getting sick during an influenza season. The researcher wants to identify the relationship between high body temperature and the getting of flu in the presence or absence of vaccination. The researcher considers the sample of 15 random people who have a high body temperature. In the result of this study, a model is built. The obtained logistic model has the form:

Chapter 13 - Multiple Linear Regression Analysis where T is body temperature and V is the flu vaccine. Assume that T and V are independent. Using this model, determine the odds ratio for a person who has your answer to four decimal places. odds ratio = ANSWER: 0.0012 POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/6/2019 7:06 AM DATE MODIFIED: 2/6/2019 8:42 AM

. Round

Chapter 14 - Analysis of Categorical Data 1. A chi-square goodness-of-fit test with 3 degrees of freedom results in a test statistic of 6.789. Using the chi-

square table, the most accurate statement that can be made about the p-value for this test is that 0.05 < p-value < 0.10. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 2. A chi-square goodness-of-fit test is always conducted as a two-tail test. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 3. A goodness-of-fit test determines the likelihood that sample data have been generated from a population that

conforms to a specified type of probability distribution. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 4. The degrees of freedom associated with a goodness-of-fit test equal the number of rows times the number of

columns in the table. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 5. All chi-square distributions are skewed to the right and their means equal the associated degrees of freedom.

Chapter 14 - Analysis of Categorical Data a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 6. Because the chi-square random variable is a sum of squares, it cannot take on negative values. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 7. A right-tailed area in the chi-square distribution equals 0.05. For 6 degrees of freedom the table value equals

12.5916. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 8. Whenever the expected frequency of a cell is less than 5, one remedy for this condition is to increase the

significance level. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 9. Whenever the expected frequency of a cell is less than 5, one remedy for this condition is to increase the size of the sample. a. True b. False

Chapter 14 - Analysis of Categorical Data ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 10. For a chi-square distributed random variable with 10 degrees of freedom and a level of significance of 0.025,

the chi-square table value is 20.4831. The computed value of the test statistics is 16.857. This will lead us to reject the null hypothesis. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 11. Whenever the expected frequency of a cell is less than 5, one remedy for this condition is to decrease the

size of the sample. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 12. The middle 0.95 portion of the chi-square distribution with 9 degrees of freedom has table values of 3.32511

and 16.9190, respectively. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 13. A left-tailed area in the chi-square distribution equals 0.10. For 5 degrees of freedom the table value equals

9.23635. a. True b. False

Chapter 14 - Analysis of Categorical Data ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 14. In applying the chi-square goodness-of-fit test, the rule of thumb for all expected frequencies is that each

expected frequency is 5 or more. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 15. The area to the right of a chi-square value is 0.01. For 8 degrees of freedom, the table value is 1.64648. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 16. A multinomial experiment, where the outcome of each trial can be classified into one of two categories, is

identical to the binomial experiment. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 17. If the test statistic for a chi-squared goodness-of-fit test is larger than the critical value, the null hypothesis

should be rejected. a. True b. False ANSWER:

True

Chapter 14 - Analysis of Categorical Data POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 18. When the expected cell frequencies are smaller than 5, the cells should be combined in a meaningful way, if

possible, such that the expected cell frequencies do exceed 5. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/11/2019 6:53 AM 19. By combining cells that have expected frequencies smaller than 5, we guard against having an inflated test

statistic that could have led us to incorrectly accept the null hypothesis. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 20. The area to the right of a chi-square value is 0.05. For 9 degrees of freedom, the table value is: a. 16.9190 b. 3.32511 c. 4.16816 d. 19.0228 e. 21.1 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 21. A chi-square goodness-of-fit test is always conducted as: a. a lower-tail test b. an upper-tail test

Chapter 14 - Analysis of Categorical Data c. a two-tail test d. either a lower tail or upper tail test ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 22. A left-tailed area in the chi-square distribution equals 0.90. For 7 degrees of freedom, the table value equals: a. 1.68987 b. 2.83311 c. 12.0170 d. 14.0671 e. 7 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 23. In a chi-square goodness-of- fit test with 5 degrees of freedom and a significance level of 0.05, the chi-

square value from the table is 11.0705. Which of the following computed values of the chi-square test statistic will lead to rejection of the null hypothesis? a. 8.952 b. 10.78 c. 7.814 d. 17.61 e. 0.25 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 24. In chi-square tests, there is a rule known as Rule of Five, which requires that: a. observed frequency for each cell be five or more b. degrees of freedom for the test be at least five c. expected frequency for each cell be five or more d. difference between the observed and expected frequency for each cell be at least five e. expected frequency for each cell be different than five

Chapter 14 - Analysis of Categorical Data ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 25. Consider a cell in a contingency table. Given the cell's row total of 80, the cell's column total of 60, and a

sample size of 250, the cell's expected frequency: a. equals 19.2 b. equals 3.125 c. equals 20.0 d. equals 1.786 e. equals 140 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 26. In a goodness-of-fit test, suppose that the value of the test statistic is 11.89 and the degrees of freedom are 5.

At the 5% significance level, the null hypothesis is: a. rejected and p-value for the test is smaller than 0.05 b. not rejected, and p-value for the test is greater than 0.05 c. rejected, and p-value for the test is greater than 0.05 d. not rejected, and p-value for the test is smaller than 0.05 e. none of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 27. To determine whether a single coin is fair, the coin was tossed 250 times, and heads was observed 140

times. The value of the test statistic is: a. 140 b. 3.6 c. 110 d. 30 e. 20 ANSWER:

Chapter 14 - Analysis of Categorical Data POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 28. In a goodness-of-fit test, suppose that a sample showed that the observed frequency

and expected

frequency were equal for each cell i. Then, the null hypothesis is: a. rejected at 0.05 but is not rejected at 0.025 b. not rejected at 0.05 but is rejected at 0.025 c. rejected at any level d. not rejected at any level e. not rejected at > 0.05 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 29. In a goodness-of-fit test, suppose that the value of the test statistic is 13.08 and the number of degrees of

freedom is 6. At the 5% significance level, the null hypothesis is: a. rejected and p-value for the test is smaller than 0.05 b. not rejected, and p-value for the test is greater than 0.05 c. rejected, and p-value for the test is greater than 0.05 d. not rejected, and p-value for the test is smaller than 0.05 e. none of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 30. If each element in a population is classified into one and only one of several categories, the population is: a. a normal population b. a multinomial population c. a chi-square population d. a binomial population e. all of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice

Chapter 14 - Analysis of Categorical Data HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 31. To determine the critical values in the chi-square distribution table, the process requires the following: a. degrees of freedom b. probability of Type I error c. probability of Type II error d. degrees of freedom and probability of Type I error e. degrees of freedom and probability of Type II error ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 32. Of the values for a chi-square test statistic listed below, which one is likely to lead to rejecting the null

hypothesis in a goodness-of-fit test? a. 0 b. 1.3 c. 1.9 d. 40 e. 1.5 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 33. If the expected frequency

for any cell i is less than 5, we:

a. must choose another sample of five or more observations b. should use the normal distribution instead of the chi-square distribution c. should combine the cells such that each expected frequency Ei is 5 or more d. increase the number of degrees of freedom for the test by 5 e. all of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM

Chapter 14 - Analysis of Categorical Data DATE MODIFIED: 4/12/2019 3:04 AM 34. Which statistical technique is appropriate when we describe a single population of qualitative data with two

or more categories? a. The z-test of the difference between two proportions. b. The chi-square goodness-of-fit test. c. The chi-square test of a contingency table. d. The z-test of the difference between two proportions and the chi-square goodness-of-fit test. e. The z-test of the difference between two proportions and the chi-square test of a contingency table. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 35. The sampling distribution of the test statistic for a goodness-of-fit test with k categories is: a. Student t distribution with k-1 degrees of freedom b. normal distribution c. chi-square distribution with k-1 degrees of freedom d. approximately chi-square distribution with k-1 degrees of freedom e. approximately chi-square distribution with k degrees of freedom ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 36. Which of the following statements is false? a. The test statistic has an approximate distribution

with k-1 degrees of freedom, where k is the

number of categories (called cells). b. The rejection region of the chi-square goodness-of-fit test is

categories and is the value of the test statistics. c. The chi-square goodness-of-fit test involves two categorical variables. d. The chi-square distribution is skewed to the right. e. None of these. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM

, where k is the number of

Chapter 14 - Analysis of Categorical Data DATE MODIFIED: 4/12/2019 3:13 AM 37. Consider a multinomial experiment with 200 trials, and the outcome of each trial can be classified into one

of 5 categories. The number of degrees of freedom associated with the chi-square goodness-of-fit test equals: a. 195 b. 40 c. 5 d. 4 e. 199 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 38. Which of the following statements is false? a. The chi-square distribution is symmetrical. b. The chi-square distribution is skewed to the right. c. All values of the chi-square distribution are positive. d. The critical region for a goodness-of-fit test with k categories is

, where

is the value of

the test statistic. e. The chi-square distribution is skewed to the right and all values of the chi-square distribution are positive. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 3:15 AM 39. Which of the following is not a characteristic of a multinomial experiment? a. The experiment consists of a fixed number, n, of trials. b. The outcome of each trial can be classified into one of two categories called successes and failure. c. The probability

that the outcome will fall into cell i remain constant for each trial. d. Each trial of the experiment is independent of the other trials. e. The experiment consists of a fixed number, n, of trials and each trial of the experiment is independent of the other trials. ANSWER:

POINTS: 1 QUESTION TYPE: Multiple Choice

Chapter 14 - Analysis of Categorical Data HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 3:18 AM 40. In the chi-square goodness-of-fit test, if there is a significant difference between the observed frequencies

and the expected frequencies Ei, we would conclude that the: a. null hypothesis is false, and we would reject it b. null hypothesis is true, and we would not reject it c. alternative hypothesis is false, and we would reject it d. chi-square distribution is invalid, and we would use the t-distribution instead ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 3:35 AM 41. If we wish to determine whether there is evidence that the proportion of successes is higher in group 1 than

in group 2, the appropriate test to use is the: a. z test b.

test c. t-test with 2 degrees of freedom d. F-test with 2 degrees of freedom e. all of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 42. If we wish to determine whether there is evidence that the proportion of successes is the same in group 1 as

in group 2, the appropriate test to use is: a. the z test b. the test c. both the z test and the test d. neither the z test nor the test ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM

Chapter 14 - Analysis of Categorical Data DATE MODIFIED: 2/4/2019 9:46 AM 43. Historically, a bank has employed 50% permanent full-time workers, 25% permanent part-time workers,

15% temporary full-time workers, and 10% temporary part-time workers. In a recent sample of 400 workers, 190 were permanent full-time, 125 were permanent part-time, 55 were temporary full-time, and 30 were temporary part-time.

Use these data and = 0.05 to assess whether there has been a change from the historical percentages. Find

. Round your answer to two decimal places.

This shows that one should Conclude that ANSWER:

. from the historical expectation. 9.67; reject; at least one of the cell probabilities differs

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 3:40 AM 44. A librarian knows from old records that the percentages of checked-out materials which are fiction,

nonfiction, children's books, books on tape, and magazines are 35%, 25%, 20%, 10%, and 10%, respectively. The material checked out in each of the categories in a recent survey of 600 randomly chosen library items is listed below.

Use these data to assess whether there has been a change in the distribution of checked-out library materials. State the hypotheses to be tested and use = 0.01 to interpret your results. The hypotheses are:

Chapter 14 - Analysis of Categorical Data

: :

from the specified value(s). Compute

. Round your answer to three decimal places.

Thus we

Conclude that

. from those specified in . .35; .25; .20; .10; .10; at least one value differs; 34.643; reject; at least one of the cell probabilities differs

ANSWER:

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 3:41 AM 45. A national survey states that 67% of college students are under the age of 25, 21% are between the ages of

25 and 30, 8% are between 30 and 40, and 4% are over 40. A random sample of 250 students at Grand Rapids Community College yielded the following data:

Test whether the distribution of students' ages at Grand Rapids Community College agrees with the national survey. Compute the value of the test statistic. Compute

. Round your answer to three decimal places.

Set up the appropriate rejection region for = 0.05. Round your answer to five decimal places. Reject

when

What is the appropriate conclusion?

Chapter 14 - Analysis of Categorical Data

. Conclude the distribution of students' ages at Grand Rapids Community College the national survey. ANSWER: 20.515; 7.81473; Reject; does not

agree with

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 3:42 AM 46. A sample survey of 850 people in Chicago was conducted in 2001 to see how people get to work. The

results are shown in the frequency table below.

A study of the same nature was conducted in 1990 and revealed 12% walk, 67% drive an automobile, 18% take a bus, and 3% ride a bicycle. Do the current data support that the proportions are the same as in 1990? Use Compute

. Round your answer to two decimal places.

One should

Conclude that the current data that the proportions in 2001 are the same as in 1990. ANSWER: 3.88; not reject; support POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 3:43 AM 47. A casino customer is concerned about whether the dice the casino are using are "fair" (i.e., each face is

equally likely to appear). The customer obtains a die that is being used by the casino and rolls it 240 times. The customer records the following data:

Chapter 14 - Analysis of Categorical Data

Compute the value of the test statistic. Round your answer to two decimal places. = Set up the appropriate rejection region for = 0.10. Round your answer to five decimal places. Reject

when

What is the appropriate conclusion? We ANSWER:

conclude that the die is fair. 5.15; 9.23635; can

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 3:44 AM 48. A total of 200 people in each of three grocery stores were asked if they favored, opposed, or were indifferent

to the sale of lottery tickets in grocery stores.

Chapter 14 - Analysis of Categorical Data

The results of the survey are summarized below. Use the MINITAB computer output shown here to conduct a chi-square test of independence at = 0.05.

The data show that one should

Thus we _ conclude that the two variables are dependent; that is, the opinion of people is not the same at the three stores. ANSWER: reject; can POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 49. A national survey stated that 30% of the population prefers to use a pen with black ink, 30% prefer blue ink,

25% prefer red ink and 15% prefer some other color. A statistics professor took a random sample of 80 students and asked them to state their ink color preference. The following data was recorded:

Chapter 14 - Analysis of Categorical Data

Test whether the data agrees with the percentages stated in the national survey. Compute the value of the test statistic. What is

? Round your answer to three decimal places.

Set up the appropriate rejection region for = 0.05. Round your answer to five decimal places. Reject

when

What is the appropriate conclusion? We conclude that the data ANSWER:

with the national survey. 2.367; 7.81473; agree

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 3:46 AM 50. A take-out pizza palace offers four different pizzas. The manager believes that 45% of the single pizza

customers prefer pepperoni pizza, 35% prefer the combination pizza, 15% prefer the taco pizza and 5% prefer the vegetarian pizza. To check his belief, the manager takes a random sample of 100 single pizza orders and records the following information:

Do the sample data present sufficient evidence to support the manager's belief? Test the appropriate hypotheses at the 10% significance level. Compute

. Round your answer to three decimal places.

Thus, one should

Conclude that the current data the manager's belief. ANSWER: 1.346; not reject; support POINTS: QUESTION TYPE: HAS VARIABLES:

1 Subjective Short Answer False

Chapter 14 - Analysis of Categorical Data STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 3:46 AM 51. The four most popular flavors of a particular brand of ice cream are French Vanilla, Natural Vanilla,

Chocolate Chip and Caramel Almond Swirl. The question arose as to whether each of these flavors is equally preferred. To answer that question, a random sample of 155 sales was selected, yielding the following data:

Compute the value of the test statistic. What is

? Round your answer to three decimal places.

Set up the appropriate rejection region for = 0.05. Round your answer to five decimal places. Reject

when

What is the appropriate conclusion? Conclude that the ice cream flavors equally preferred. ANSWER: 13.387; 7.81472; are not POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 4:01 AM 52. A survey in Southern California claims that, among consumers, the grocery store chains of Ralph's, Lucky's,

and Von's are equally preferable. To check this claim, a random sample of 150 consumers was selected and the following data recorded:

Test the appropriate hypotheses at the 5% significance level. Compute

. Round your answer to two decimal places.

Chapter 14 - Analysis of Categorical Data

Reject

when

. Round your answer to five decimal places.

Conclude that the three grocery store chains ANSWER: 2.56; 5.99147; are

equally preferred.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 4:05 AM 53. A sports enthusiast believes that among sports television viewers 60% prefer to watch football, 25% prefer

basketball and 15% prefer hockey. A random sample of 120 viewers was selected and the following data recorded:

Perform the appropriate test of hypothesis to determine whether the percentages are correct. Use = 0.05. Compute

Reject

. Round your answer to two decimal places.

when

. Round your answer to five decimal places.

Conclude that the data support the stated percentages; that is, the sports enthusiast's belief correct. ANSWER: 4.44; 5.99147; is POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 4:04 AM 54. Suppose that a response can fall into one of k = 5 categories with probabilities

, and that n =

250 responses produced these category counts:

Are the five categories equally likely to occur? If you were to test this hypothesis using the chi-square statistic, how many degrees of freedom would the test

Chapter 14 - Analysis of Categorical Data

have?

Compute

. Round your answer to two decimal places.

Set up the appropriate rejection region for = 0.05. Round your answer to five decimal places. Reject

when

Conclude that the five salespersons ANSWER: 4; 6.32; 9.487; are

equally like to sell cars.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 4:15 AM 55. A peony plant with red petals was crossed with another plant having streaky petals. A geneticist states that

80% of the offspring from this cross will have red flowers. To test this claim, 100 seeds from this cross were collected and germinated, and 65 plants had red petals. Use the chi-square goodness-of-fit test to determine whether the sample data confirm the geneticist's prediction. Find the approximate p-value and use it to make your decision. Compute

. Round your answer to four decimal places.

Set up the appropriate rejection region for = 0.005. Round your answer to five decimal places. Reject

when

The p-value

. .

We have sufficient evidence to conclude that the geneticist's model Use the large-sample z-test to test the hypothesis H0: p = 0.80. Compute the z-statistic.

The p-value

correct.

Chapter 14 - Analysis of Categorical Data

We have sufficient evidence to conclude that the geneticist's model ANSWER: 14.0625; 7.87944; < .005; is not; -3.75; < .005; is not

correct.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 4:21 AM 56. Researchers from Germany claimed that the risk of a heart attack for a working person may be as much as

50% greater on Monday than on any other day. In an attempt to verify their claim, they surveyed 420 working people who had recently had heart attacks and recorded the day on which their heart attacks occurred:

Do the data present sufficient evidence to indicate that there is a difference in the incidence of heart attacks depending on the day of the week? Test using = 0.05. Compute

Reject

. Round your answer to three decimal places.

when

Conclude that there is attack from day to day. ANSWER:

. Round your answer to two decimal places. evidence to indicate a difference in frequency of occurrence of a heart 7.867; 12.59; insufficient

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 4:27 AM 57. Medical statistics show that deaths due to four major diseases - call them A, B, C and D - account for 15%,

21%, 18%, and 14%, respectively, of all non-accidental deaths. A study of the causes of 616 non-accidental deaths at a hospital give the following counts:

Do these data provide sufficient evidence to indicate that the proportions of people dying of diseases A, B, C, and D at this hospital differ from the proportions accumulated for the population at large?

Chapter 14 - Analysis of Categorical Data

Find the approximate p-value and use it to make your decision. Compute

. Round your answer to three decimal places.

Set up the appropriate rejection region for = 0.005. Round your answer to four decimal places. Reject

when

Thus the p-value

. .

Conclude that the proportions of people dying of diseases A, B, C, and D at this hospital the proportions for the larger population. ANSWER: 63.535; 14.8602; < .005; differ

from

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 4:28 AM 58. A firm has been accused of engaging in prejudicial hiring practices. According to the most recent census, the

percentages of whites, blacks, and Hispanics in a certain community are 72%, 10%, and 18%, respectively. A random sample of 200 employees of the firm revealed that 165 were white, 14 were black, and 21 were Hispanic. Do the data provide sufficient evidence to conclude at the 5% level of significance that the firm has been engaged in prejudicial hiring practices? Compute

Reject

. Round your answer to three decimal places.

when

Conclude that the firm _ ANSWER:

. Round your answer to three decimal places. engaged in prejudicial hiring practices 11.113; 5.991; has been

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 4:30 AM 59. Five brands of orange juice are displayed side by side in several supermarkets in the city of Chicago. It

was noted that in one day, 180 customers purchased orange juice. Of these, 30 picked Brand A, 40 picked Brand B, 25 picked Brand C, 35 picked Brand D, and 50 picked brand E. In Chicago, can you conclude at the

Chapter 14 - Analysis of Categorical Data

significance level that there is a preferred brand of orange juice? Compute

Reject

. Round your answer to three decimal places.

when

. Round your answer to three decimal places.

Conclude that there

preferred brand of orange juice in Chicago. 10.278; 9.488; is a

ANSWER:

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 4:30 AM 60. In 2003, the student body of a state university in Michigan consists of 30% freshmen, 25% sophomores,

27% juniors, and 18% seniors. A sample of 400 students taken from the 2004 student body showed that there are 138 freshmen, 88 sophomores, 94 juniors, and 80 seniors. Test with 5% significance level to determine whether the student body proportions have changed. = Critical Value =

Round your answer to three decimal places. Round your answer to three decimal places.

Conclusion: There ANSWER:

evidence that the student body proportions have changed since 2003. 6.844; 7.815; Do not reject H0;is not

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 4:43 AM 61. In 2003, Brand A microwaves had 45% of the market, Brand B had 35%, and Brand C had 20%. This year

the makers of Brand C launched a heavy advertising campaign. A random sample of appliance stores shows that of 10,000 microwaves sold, 4350 were Brand A, 3450 were Brand B, and 2200 were Brand C. Has the market changed? Test at = 0.01. = Critical Value(s) =

Round your answer to three decimal places. Round your answer to three decimal places.

Chapter 14 - Analysis of Categorical Data

Conclusion: The market

changed since 2003.

ANSWER:

25.714; 9.210; Reject H0; has

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 4:45 AM 62. Consumer panel preferences for three proposed fast food restaurants are as follows:

Use 0.05 level of significance and test to see if there is a preference among the three restaurants. = Critical Value =

Round your answer to two decimal places. Round your answer to three decimal places.

Conclusion: There ANSWER:

evidence that there is a preference among the three restaurants. 4.96; 5.991; Do not reject H0; is no

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 4:47 AM 63. A cafeteria proposes to serve 4 main entrees. For planning purposes, the manager expects that the

proportions of each that will be selected by his customers will be:

Of the first 100 customers, 44 selected chicken, 24 selected roast beef, 13 select steak, and 10 selected fish.

Chapter 14 - Analysis of Categorical Data

Should the manager revise his estimates? Use = 0.01. =

Round your answer to two decimal places.

Critical Value(s) =

Round your answer to three decimal places.

Conclusion: The manager

revise his estimates.

ANSWER:

7.26; 11.345; Do not reject H0; should not

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 4:48 AM 64. A statistics professor posted the following grade distribution guidelines for his elementary statistics class:

8% A, 35% B, 40% C, 12% D, and 5% F. A sample of 100 elementary statistics grades at the end of last semester showed 12 As, 30 Bs, 35 Cs, 15 Ds, and 8 Fs. Test at the 5% significance level to determine whether the actual grades deviate significantly from the posted grade distribution guidelines. =

Round your answer to three decimal places.

Critical Value =

Round your answer to three decimal places.

Conclusion: The actual grades

from the posted grade distribution guidelines.

ANSWER:

5.889; 9.488; Do not reject H0; do not deviate

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 4:49 AM 65. A contingency table classifies data with respect to two qualitative variables that are each divided into two or

more categories. a. True b. False ANSWER: POINTS:

True 1

Chapter 14 - Analysis of Categorical Data QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 66. Numbers in a contingency table show the frequency of occurrence of all possible combinations of

categories. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 67. In a typical chi-square test of independence, we calculate each expected cell frequency (

) as the product of

row total ( ) times column total ( ) times sample size (n). a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 68. Chi-square tests of independence are always lower-tailed because a perfect fit between

test statistic

and

makes the

equal to zero.

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 69. To be valid, a chi-square test of independence requires that the expected frequency for each cell in the

contingency table equal 10 or more. a. True b. False

Chapter 14 - Analysis of Categorical Data ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 70. The degrees of freedom associated with a chi-square test of independence where data are summarized in a

contingency table with r rows and c columns equal the number of rows times the number of columns in the table; that is, rc. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 71. The chi-square test statistic for a contingency table with r rows and c columns can be negative if r is much

smaller than c. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 72. A chi-square test for independence is applied to a contingency table with 3 rows and 5 columns for two

qualitative variables. The degrees of freedom for this test is 8. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 73. In a chi-square test of independence with 6 degrees of freedom and a level of significance of 0.05, the

critical value from the chi-square table is 12.5916. The computed value of the test statistics is 11.264. This will lead us to reject the null hypothesis. a. True

Chapter 14 - Analysis of Categorical Data b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 74. An r × c contingency table results when each of n experimental units is counted as falling into (r +c)th cells

of a multinomial experiment. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 6:15 AM 75. If there are more than two row categories with fixed column totals in the contingency table, then the test of

independence is equivalent to a test of the equality of r × c sets of multinomial proportions. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 6:15 AM 76. In a typical contingency-table test, we calculate each expected cell frequency as the product of row total

times column total times sample size. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 77. Chi-square tests of independence are always lower-tailed because a perfect fit between

equal to zero. a. True

and

makes

Chapter 14 - Analysis of Categorical Data b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 78. A contingency table classifies data according to two or more categories associated with each of two

qualitative variables that are statistically independent of one another. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 79. The degrees of freedom associated with a contingency-table test of independence equal the number of rows

times the number of columns in the table. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 80. To be valid, a chi-square test of independence requires that each expected frequency equal 30 or more. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 81. A chi-square test for independence is applied to a contingency table with 3 rows and 4 columns for two

qualitative variables. The degrees of freedom for this test must be 12. a. True b. False

Chapter 14 - Analysis of Categorical Data ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 82. A chi-square test for independence is applied to a contingency table with 4 rows and 4 columns for two

qualitative variables. The degrees of freedom for this test must be 9. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 83. A chi-square test for independence with 10 degrees of freedom results in a test statistic of 17.894. Using the

chi-square table, the most accurate statement that can be made about the p-value for this test is that 0.05 < pvalue < 0.10. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 84. In a chi-square test of independence, the value of the test statistic was

was 11.1433. Thus, we must reject the null hypothesis at

15.652, and the critical value at .

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 85. The chi-square test of independence is based upon three or more quantitative variables. a. True b. False

Chapter 14 - Analysis of Categorical Data ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 86. A chi-square test for independence with 6 degrees of freedom results in a test statistic of 13.25. Using the

chi-square table, the most accurate statement that can be made about the p-value for this test is that p-value is greater than 0.025 but smaller than 0.05. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 87. The chi-square test of a contingency table is used to determine if there is enough evidence to infer that two

nominal variables are related, and to infer that differences exist among two or more populations of nominal variables. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 88. A chi-square test of independence with 10 degrees of freedom results in a test statistic of 19.25. Using the

chi-square table, the most accurate statement that can be made about the p-value for this test is that: a. p-value < 0.025 b. 0.025 < p-value < 0.05 c. 0.05 < p-value < 0.10 d. 0.10 < p-value < 0.20 e. p-value > 0.2 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM

Chapter 14 - Analysis of Categorical Data 89. The chi-square test of independence is based upon: a. two qualitative variables b. two quantitative variables c. three or more qualitative variables d. three or more quantitative variables e. a quantitative and a qualitative variable ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 90. A chi-square test of independence is applied to a contingency table with 4 rows and 5 columns for two

qualitative variables. The degrees of freedom for this test will be: a. 20 b. 16 c. 15 d. 12 e. 9 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 91. In a chi-square test of independence, the value of the test statistic was

= 9.572, and the critical value at

was 11.1433. Thus, a. we fail to reject the null hypothesis at b. we reject the null hypothesis at c. we don't have enough evidence to accept or reject the null hypothesis at d. we should decrease the level of significance in order to reject the null hypothesis e. none of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM

Chapter 14 - Analysis of Categorical Data 92. A contingency table test with 4 rows and 15 degrees of freedom implies: a. 5 columns b. 6 columns c. 9 columns d. 11 columns e. 60 columns ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 93. A contingency table: a. classifies data with respect to two qualitative variables b. divides each variable into two or more categories c. contains numbers that show the frequency of occurrence of all possible combinations of categories d. all of these e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 94. Consider a cell in a contingency table. Given the cell's row total of 200, the cell's column total of 75, and a

sample size of 1,000, the cell's expected frequency: a. equals 10 b. equals 15 c. equals 20 d. equals 25 e. cannot possibly be determined without additional information ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 95. Which of the following statements about a contingency table test is false? a. The nature of the sampling distribution of chi-square depends on the number of degrees of freedom

associated with the problem under investigation.

Chapter 14 - Analysis of Categorical Data b. The degrees of freedom are found as (r - 2)(c - 2), where r represents number of rows and c

represents number of columns. c. The contingency table must have a minimum of 2 rows and 2 columns. d. All of these. e. None of these. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 96. Which of the following statements about the chi-square distribution is false? a. A different chi-square distribution exists for each possible number of degrees of freedom. b. Because the chi-square random variable is a sum of squared deviations, negative values are

impossible. c. All values range between zero and one. d. All chi-square distributions are skewed to the right. e. All of these. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 97. Which of the following statements about a goodness-of-fit test is false? a. The rejection region and p-value are in the upper tail of the chi-square distribution. b. It compares the entire shapes of two (discrete or continuous) probability distributions: one describing

known population data and the other one describing hypothetical sample data. c. The test statistic has degrees of freedom equal to the number of categories minus one because the only linear restriction on the cell probabilities is that their sum must be equal 1. d. The cells of a sample frequency histogram correspond to the k cells of a multinomial experiment. e. None of these. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 6:27 AM 98. A contingency table test with 4 rows and 30 degrees of freedom implies that the table must have: a. 7 columns

Chapter 14 - Analysis of Categorical Data b. 9 columns c. 11 columns d. 13 columns e. 15 columns ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 99. The president of a state university collected data from students concerning building a new library, and

classified the responses into different categories (strongly agree, agree, undecided, disagree, strongly disagree) and according to whether the student was male or female. To determine whether the data provide sufficient evidence to indicate that the responses depend upon gender, the most appropriate test is: a. chi-square goodness-of-fit test b. chi-square test of a contingency table (test of independence) c. chi-square test of normality d. none of these e. all of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 100. The number of degrees of freedom for a contingency table with 6 rows and 6 columns is: a. 36 b. 25 c. 12 d. 6 e. 0 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 101. A chi-square test of a contingency table with 4 rows and 5 columns shows that the value of the test statistic

is 22.18. The most accurate statement that can be made about the p-value for this test is that: a. p-value is greater than 0.05 but smaller than 0.10

Chapter 14 - Analysis of Categorical Data b. p-value is smaller than 0.025 c. p-value is greater than 0.025 but smaller than 0.05 d. p-value is greater than 0.10 e. Not enough information is given to determine the p- value. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 6:34 AM 102. Which statistical technique is appropriate when we wish to analyze the relationship between two qualitative

variables with two or more categories? a. The chi-square test of a multinomial experiment. b. The chi-square test of a contingency table. c. The t-test of the difference between two means. d. The z test of the difference between two proportions. e. None of these. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 103. Contingency tables are used in: a. testing independence of two samples b. testing dependence in matched pairs c. testing independence of two populations d. describing a single population e. testing independence of two quantitative variables in a population ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 104. The chi-square test of a contingency table is based upon: a. two qualitative variables b. two quantitative variables c. three or more qualitative variables d. three or more quantitative variables

Chapter 14 - Analysis of Categorical Data e. all of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 105. A market research study was conducted to compare three different brands of car oil. The results of the

study are summarized below.

Use the accompanying MINITAB output and = 0.005 to determine whether the brand of oil is independent of opinion. Compute

Reject

when

Round your answer to three decimal places. > .............................. Round your answer to four decimal places.

Conclude that the two variables are . ANSWER: 44.192; 14.8602; dependent POINTS: QUESTION TYPE:

1 Subjective Short Answer

Chapter 14 - Analysis of Categorical Data HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 6:36 AM 106. The owner of Fit Forever Health Club is considering adding an indoor swimming pool to his facility. The

manager decided to take a survey to determine whether member opinion about the addition of a pool was independent of the age of the member. Two hundred members were selected at random and asked to state their opinion. The following data was recorded:

What is

? Round your answer to three decimal places.

What is the p-value associated with the test? Round your answer to three decimal places.

Use the significant level α = 0.05. Conclude that member's opinion concerning the addition of an indoor pool is age. ANSWER: 12.562; .014; dependent on POINTS:

the member's

Chapter 14 - Analysis of Categorical Data QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 6:40 AM 107. A pollster was interested in determining whether three television dramas are equally preferable among men

and women. The following data was recorded:

Compute

Round your answer to four decimal places.

Use the significant level α = 0.05. Round your answer to five decimal places. Reject

when

Conclude that the preference of television drama is ANSWER: 2.6786; 5.99147; independent of

the viewer's gender.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 6:42 AM 108. A marketing research professor at Ferris State University conducted a survey to determine whether mode of

transportation to the university and the person's position at the university were independent. The following data was recorded:

Perform the appropriate test of hypothesis using = 0.10. Compute

Reject

when

Round your answer to three decimal places. > .............................. Round your answer to four decimal places.

Conclude that the mode of transportation to the university and person's position at the university are

Chapter 14 - Analysis of Categorical Data

. ANSWER:

14.454; 10.6446; dependent

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 6:43 AM 109. A study was conducted to determine whether opinion concerning the addition of seat belts in school buses

is independent of the population density in which a person resides. The following data was recorded:

Use the following output generated using Minitab to answer the questions below.

What is

? Round your answer to three decimal places.

Use the significant level α = 0.05. Round your answer to three decimal places. What is the p-value associated with the test?

Chapter 14 - Analysis of Categorical Data

Conclude that opinion concerning the addition of seat belts to school buses is density where the person resides. ANSWER: 4.003; .406; independent of

the population

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 6:45 AM 110. A survey of 500 respondents produced these cell counts in a 2 3 contingency table:

If you wish to test the null hypothesis of "independence" - that the probability that a response falls in any one row is independent of the column it falls in - and you plan to use a chi-square test, how many degrees of freedom will be associated with the statistic? df = Compute

Round your answer to four decimal places.

Use the significant level α = 0.01. Round your answer to five decimal places. Reject

when

Conclude that there

. reason to expect a dependence between rows and columns.

Find the approximate p-value for the test. The p-value .............................. 10 ANSWER: 2; 4.1879; 9.21034; is not; > POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 6:48 AM 111. Is there a difference in the spending patterns of high school seniors depending on their gender? A study to

investigate this question focused on 196 employed high school seniors. Students were asked to classify the

Chapter 14 - Analysis of Categorical Data

amount of their earnings that they spent on their car during a given month:

A portion of the Minitab printout is given here.

Use the printout to analyze the relationship between spending patterns and gender. What is

? Round your answer to three decimal places.

Use the significant level α = 0.05. Round your answer to three decimal places. What is the p-value?

Conclude that there males and females. ANSWER:

sufficient evidence to indicate a difference in spending patterns between 6.696; .153; is not

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 6:49 AM 112. The number of Americans who visit fast-food restaurants regularly has grown steadily over the last decade.

For this reason, marketing experts are interested in the demographics of fast-food customers. Is a customer's preference for a fast- food chain affected by the age of the customer? If so, advertising might need to target a particular age group. Suppose a random sample of 400 fast-food customers aged 16 and older was selected, and their favorite fast-food restaurants along with their age groups were recorded, as shown in the table:

Chapter 14 - Analysis of Categorical Data

Use an appropriate method to determine whether or not a customer's fast-food preference is dependent on age. Compute

. Round your answer to three decimal places.

Use the significant level α = 0.05. Round your answer to three decimal places. What is the p-value?

Conclude that there

a dependence between age group and favorite fast food restaurant.

Write a short paragraph presenting your statistical conclusions and their practical implications for marketing experts.

ANSWER:

24.873; .003; is; The practical implications of this conclusion can be explored by looking at the conditional distribution of fast food choices for each of the four age groups.

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 6:50 AM 113. An experiment was conducted to investigate the effect of general hospital experience on the attitudes of

physicians toward lower-class people. A random sample of 50 physicians who had just completed 4 weeks of service in a general hospital were categorized according to their concern for lower-class people before and after their general hospital experience. The data are shown in the table.

Do the data provide sufficient evidence to indicate a change in "concern" after the general hospital experience? Compute

Round your answer to four decimal places.

Give a range for the p-value. Conclude that there is

enough evidence to indicate a change in concern due to the general

Chapter 14 - Analysis of Categorical Data

hospital experience. ANSWER:

8.0026; Smaller than .005; is

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 6:52 AM 114. The personnel manager of a consumer products company asked a random sample of employees how they

felt about the work they were doing. The following table gives a breakdown of their responses by age.

Is there sufficient evidence to conclude that the level of job satisfaction is related to age? Use = 0.10. What is

? Round your answer to three decimal places.

Critical Value =

Round your answer to three decimal places.

Conclusion: Job satisfaction ANSWER:

related to age. 9.692; 7.779; Reject H0; is

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 6:53 AM 115. A sport preference poll showed the following data for men and women:

Use the 5% level of significance and test to determine whether sport preferences depend on gender.

Chapter 14 - Analysis of Categorical Data

Round your answer to two decimal places.

Critical Value =

Round your answer to three decimal places.

Conclusion: Sport preferences

on gender.

ANSWER:

3.30; 9.488; Do not reject H0; don't depend

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 6:54 AM 116. A study of educational levels of 500 voters and their political party affiliations in a southern state in the

USA showed the following results:

Use the 1% level of significance and test to see if party affiliation is independent of the educational level of the voters. =

Round your answer to three decimal places.

Critical Value =

Round your answer to three decimal places.

Conclusion: Political party affiliation ANSWER:

on the educational level of the voters. 26.830; 13.277; Reject H0; depends

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 6:54 AM 117. A major insurance firm interviewed a random sample of 1200 college students to find out the type of life

insurance preferred, if any. The results follow:

Chapter 14 - Analysis of Categorical Data

Is there evidence that life insurance preference of male students is different than that of female students? Test using the 5% level of significance. Test statistic =

Round your answer to three decimal places.

Critical Value =

Round your answer to three decimal places.

Conclusion: Life insurance preference ANSWER:

on gender. 15.124; 5.991; Reject H0; depends

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 6:54 AM 118. The personnel manager of a consumer product company asked a random sample of employees how they

felt about the work they were doing. The following table gives a breakdown of their responses by gender.

Do the data provide sufficient evidence to conclude that the level of job satisfaction is related to gender? Conduct the test at the 0.10 level of significance. Test statistic = Critical Value(s) =

Round your answer to three decimal places. Round your answer to three decimal places.

Conclusion: The data provide

evidence to conclude that the level of job satisfaction is related to gender.

ANSWER:

4.708; 4.605; Reject H0; sufficient

POINTS: QUESTION TYPE:

1 Subjective Short Answer

Chapter 14 - Analysis of Categorical Data HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 6:55 AM 119. A large carpet store wishes to determine if the brand of carpet purchased is related to the purchaser's family

income. As a sampling frame, they mailed a survey to people who have a store credit card. Five hundred customers returned the survey and the results follow:

At the 5% level of significance, can you conclude that the brand of carpet purchased is related to the purchaser's family income? Test statistic =

Round your answer to three decimal places.

Critical Value =

Round your answer to three decimal places.

Conclusion: We can conclude that the brand of carpet purchased ANSWER:

related to the purchaser's family income.

27.372; 9.488; Reject H0; is

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 6:55 AM 120. If we want to perform a two-tail test for differences between two populations of nominal data with exactly

two categories, we can employ either the z-test of , or the chi-square test of homogeneity, since squaring the value of the z statistic yields the value of statistics. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/23/2019 4:34 AM

Chapter 14 - Analysis of Categorical Data 121. The chi-square technique is a statistical technique for testing the alleged independence of two qualitative

variables, making inferences about the relative sizes of more than two population proportions, and conducting goodness-of-fit tests to assess the plausibility that sample data come from a population that conforms to a specified probability distribution. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 122. When there are only 2 categories in a multinomial experiment, the experiment reduces to a binomial

experiment. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 123. The data that result from two binomial experiment can be displayed as a two-way classification with 2 rows

and 2 columns, so that the chi-square test of homogeneity can be used to compare the two binomial proportions and . a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 124. The goodness-of-fit test is a two-way classification will cell probabilities specified in a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM

Chapter 14 - Analysis of Categorical Data DATE MODIFIED: 2/4/2019 9:46 AM 125. When either the row or column totals in a contingency table are fixed, the test of independence of

classifications becomes a test of the homogeneity of cell probabilities for several multinomial experiments. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 126. The large-sample z tests for one and two binomial proportions are special cases of the chi-square statistic. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 127. All expected cell counts must equal ten in order that the chi-square approximation is valid. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 128. Tests of homogeneity are used to compare several binomial populations. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 129. If there are more than two row categories in a contingency table with fixed c column totals, then the test of

independence is equivalent to a test of the equality of c sets of multinomial proportions.

Chapter 14 - Analysis of Categorical Data a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 130. The total degrees of freedom for an r × c (fixed-column) contingency table are rc + 1. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/23/2019 5:13 AM 131. If we want to conduct a one-tail test of a population proportion, we can employ: a. z-test of a population proportion b. the chi-square goodness-of-fit test since c. the chi-square test of independence d. none of these e. all of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/23/2019 5:40 AM 132. If we want to conduct a two-tail test of a population proportion, we can employ: a. z-test of a population mean b. the chi-square goodness-of-fit test since c. the chi-square test of independence

and z-test of a population mean

d. z-test of a population proportion and the chi-square goodness-of-fit test since e. z-test of a population proportion and the chi-square test of independence ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice

Chapter 14 - Analysis of Categorical Data HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 7:04 AM 133. The chi-square technique has numerous applications, including: a. testing the alleged independence of two qualitative variables b. making inferences about the relative sizes of more than two population proportions c. conducting a goodness-of-fit-test to determine whether data are consistent with data drawn from a

particular probability distribution d. all of these e. none of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 134. To be valid, the chi-square test requires that all expected frequencies equal: a. 30 or more b. 30 or less c. 30 precisely d. both 30 or more and 30 or less e. none of these ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 2/4/2019 9:46 AM 135. The following table shows the results of a study in which random samples of 200 members of each of five

large unions were asked whether they are for, undecided, or against a certain piece of legislation.

Use the 0.025 level of significance to test whether the unions differ with respect to their views. Compute

Reject

when

Round your answer to three decimal places. > ............................... Round your answer to four decimal places.

Chapter 14 - Analysis of Categorical Data

Conclude: The unions

different views. 71.178; 17.5346; have

ANSWER:

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 7:06 AM 136. Suppose you wish to test the null hypothesis that three binomial parameters

, , and are equal versus the alternative hypothesis that at least two of the parameters differ. Independent random samples of 100 observations were selected from each of the populations. The data are shown in the table:

Write the null and alternative hypotheses for testing the equality of the three binomial proportions. : Test statistic: =

Round your answer to four decimal places.

What is the p-value? Use the significant level α = 0.05. Round your answer to three decimal places.

. There is _ sufficient evidence to indicate that the proportions depend upon the population from which they were drawn. ANSWER: For all i,j; 5.0682; .0793; Do not reject; insufficient POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 7:07 AM

Chapter 14 - Analysis of Categorical Data 137. A study of the purchase decisions of three stock portfolio managers, A, B, C, was conducted to compare the

numbers of stock purchases that resulted in profits over a time period less than or equal to 1 year. One hundred randomly selected purchases were examined for each of the managers.

Do the data provide evidence of differences among the rates of successful purchases for the three managers? Compute

Round your answer to four decimal places.

Use the significant level α = 0.05. The p-value is

Conclude that there enough information to conclude that the proportion of successful purchases will differ among the managers. ANSWER: 5.6264; between .05 and .10; is not POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:46 AM DATE MODIFIED: 4/12/2019 7:11 AM 138. According to the data of IRIS (https://www.iris.edu/hq/), the number of earthquakes in the Japan region stabilized after a very strong earthquake in Fukushima in 2011. The table below presents data of strong earthquakes with magnitude more than 6 in this region since 2012 year. 2012 2013 2014 2015 2016 2017

Number of earthquakes

Using the provided data, determine whether the number of earthquakes in Japan has been approximately constant since 2012. What is the p- value and what is your conclusion? Use a .05 level of significance. a. p-value = 0.270; there is not enough evidence to conclude that the number of earthquakes in Japan is changing. b. p-value = 0.270; there is enough evidence to conclude that the number of earthquakes in Japan is changing. c. p-value = 0.107; there is not enough evidence to conclude that the number of earthquakes in Japan is changing. d. p-value = 0.107; there is enough evidence to conclude that the number of earthquakes in Japan is changing. e. p-value = 0.381; there is enough evidence to conclude that the number of earthquakes in Japan is changing. ANSWER: a POINTS: 1

Chapter 14 - Analysis of Categorical Data QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 2:31 AM DATE MODIFIED: 2/6/2019 3:33 AM 139. In a small town, there are two veterinary clinics, one is in the city center and the other is on the outskirts. A young veterinarian wants to understand whether there is a difference between the types of patients in these two clinics. To do this, the veterinarian wants to use the data about all patients of certain animals that undergo treatment in both clinics for a month.

clinic 1 clinic 2

dogs 25 18

cats 19 11

hamsters parrots hourses swine 3 5 2 0 0 2 6 4

hens 0 12

Assuming that the data is quite random, determine whether there is a difference between the species of animals that are undergoing treatment in the clinics. What is the chi-square value, the critical value, and what is your conclusion? Use a .05 level of significance. a.

; critical value of χ2 is 12.592; there is enough evidence to conclude that the difference between the species of animals that are undergoing treatment in the clinics exists.

; critical value of χ2 is 14.067; there is enough evidence to conclude that the difference between the species of animals that are undergoing treatment in the clinics exists.

; critical value of χ2 is 12.592; there is not enough evidence to conclude that the difference between the species of animals that are undergoing treatment in the clinics exists.

; critical value of χ2 is 14.067; there is not enough evidence to conclude that the difference between the species of animals that are undergoing treatment in the clinics exists.

; critical value of χ2 is 25.551; there is enough evidence to conclude that the difference between the species of animals that are undergoing treatment in the clinics exists. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 2:50 AM DATE MODIFIED: 2/6/2019 3:47 AM 140. It is known that a blood sugar level of about 5.8 mmol/L is considered normal. There is a serious risk of diabetes when the blood sugar level is elevated. However, if the blood test shows a slightly elevated glucose level, the diagnosis of diabetes is often not confirmed. To investigate the relationship between the blood sugar level in the primary test and the final diagnosis, a sample of 109 randomly taken people was examined. Diabets Total Present Absent Level < 7 4 49 53

Chapter 14 - Analysis of Categorical Data Level > 7 Total

19 23

37 86

56 109

Using this data and a technology application (like Minitab), build a log-linear model of this study and make a test for significance. What is the chi-square value, the critical value, and what is your conclusion? Use a .01 level of significance. a.

; critical value of χ2 is 6.635; there is enough evidence to conclude that the relationship between the blood sugar level in the primary test and diabetes exists.

; critical value of χ2 is 9.210; there is enough evidence to conclude that the relationship between the blood sugar level in the primary test and diabetes exists.

; critical value of χ2 is 6.635; there is not enough evidence to conclude that the relationship between the blood sugar level in the primary test and diabetes exists.

; critical value of χ2 is 9.210; there is not enough evidence to conclude that the relationship between the blood sugar level in the primary test and diabetes exists.

; critical value of χ2 is 12.228; there is enough evidence to conclude that the relationship between the blood sugar level in the primary test and diabetes exists. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/6/2019 3:34 AM DATE MODIFIED: 2/6/2019 3:48 AM

Chapter 15 - Nonparametric Statistics 1. The Wilcoxon rank sum test is a nonparametric test that measures the degree of association between two

when the assumptions for a t-test are invalid. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 3. Nonparametric statistical methods generally specify hypotheses in terms of population distributions rather

than parameters such as means and standard deviations. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 4. A parametric test is a hypothesis test that depends on certain specific assumptions about the probability

distribution of population values or the sizes of population parameters. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 5. Nonparametric tests are methods of inference that make no assumptions whatsoever about the nature of

Chapter 15 - Nonparametric Statistics

underlying population distributions or their parameters. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 6. The Wilcoxon rank-sum test is a nonparametric test that uses two independent simple random samples to

determine whether the relative frequency distributions of two statistical populations of continuous values are identical to or different from one another. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 7. The Mann-Whitney U test is a nonparametric test that measures the degree of association between two

variables for which only rank-order data are available. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 4/22/2019 1:34 AM 8. Statistical tests that are not very sensitive to errors in assumptions are called parametric tests. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 9. Nonparametric tests are often more efficient than parametric tests. a. True

Chapter 15 - Nonparametric Statistics b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 10. Parametric assumptions are often replaced by more general assumptions about the population distributions,

and the ranks of the observations are often used in place of the actual measurements. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 4/15/2019 3:40 AM 11. When sample sizes are small and the original populations are not normal, use nonparametric techniques. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 4/15/2019 3:40 AM 12. A nonparametric test is one that makes no assumptions about the specific shape of the population from

which a sample is drawn. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 13. A Wilcoxon rank sum test and Mann–Whitney U-test are not equivalent in that they use the different sample

information. a. True b. False

Chapter 15 - Nonparametric Statistics ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 4/16/2019 3:27 AM 14. A Wilcoxon rank sum test for comparing two independent samples involves two samples of sizes 6 and 9.

The alternative hypothesis is that the location of population 1 is to the left of the location of population 2. Using a 0.05 significance level, the appropriate critical values are 31 and 65. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 15. In a Wilcoxon rank sum test for independent samples, the two sample sizes are 4 and 6, and the value of the

Wilcoxon test statistic is T = 25. If the test is a two-tail and the level of significance is 0.05, then the null hypothesis will be rejected. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 16. A Wilcoxon rank sum test for comparing two populations involves two independent samples of sizes 15 and

20. If the value of un-standardized test statistic is T = 225, then the value of the standardized test statistic is z = 1.50. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 17. The statistical methods discussed in this chapter are used to test characteristics of populations without

referring to specific parameters. For this reason, these techniques are called nonparametric techniques.

Chapter 15 - Nonparametric Statistics a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 18. The Wilcoxon rank sum test is used to compare two populations when the samples are independent but not

normally distributed. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 19. In a normal approximation to the Wilcoxon rank sum test, the standardized test statistic is calculated as z =

1.96. For a two-tail test, the p-value of the test is 0.025. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 20. The Wilcoxon rank-sum test is a nonparametric test that uses two independent simple random samples to

determine whether the relative frequency distributions of two statistical populations of continuous values are identical to or different from one another. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 21. The z-test approximation to the Wilcoxon rank sum test for two independent samples requires that both

sample sizes are smaller than 10.

Chapter 15 - Nonparametric Statistics a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 22. A Wilcoxon rank sum test for comparing two independent samples involves two samples of sizes 6 and 10.

The alternative hypothesis is that the location of population 1 is different from the location of population 2. Using a 0.05 significance level, the appropriate critical value is 32. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 23. The procedure for the Wilcoxon rank sum test requires that we rank each group separately rather than

together. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 24. Which one of the following statements correctly states the difference between parametric and nonparametric

statistical methods? a. Nonparametric tests do not make any distributional assumptions throughout the entire process. b. Nonparametric tests do not have the hypotheses based on population parameters or assumptions based on the distributions of populations from which the samples are drawn. c. Nonparametric tests involve only interval data whereas parametric tests involve only ordinal data. d. Nonparametric tests are involved with populations which have no parameters. e. None of these. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False

Chapter 15 - Nonparametric Statistics DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 25. A two-sample t-test with independent samples corresponds to: a. a Wilcoxon signed rank test for paired samples b. a Wilcoxon rank sum test c. a Wilcoxon signed rank test for one sample d. a Friedman test for randomized block design e. a chi-square test ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 26. Comparing the output of strawberries grown on plots using fertilizer A with that grown on otherwise

identical plots using fertilizer B, in order to make a general assessment of relative fertilizer effectiveness, may well call for: a. the sign test b. Kruskal-Wallis test c. Wilcoxon rank-sum test d. Wilcoxon signed-rank test e. either Kruskal-Wallis test or Wilcoxon rank-sum test ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 4/15/2019 4:19 AM 27. Nonparametric tests can be appropriate for quantitative data when: a. one or more of the assumptions underlying a particular parametric statistical test has been violated b. the sample size is very large c. the underlying population can be assumed to be normally distributed d. all assumptions for a particular parametric statistical test have been met e. none of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM

Chapter 15 - Nonparametric Statistics DATE MODIFIED: 2/4/2019 9:48 AM 28. You are performing the Wilcoxon rank-sum test. The 10th through 12th values in an ordered array of pooled

sample data all equal $100, while the 9th value is less than $100 and the 13th value is more than $100. The appropriate ranks for the three $100 values are: a. 9, 9, 9 b. 10, 10, 10 c. 11, 11, 11 d. 12, 12, 12 e. 13, 13, 13 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 29. Which of the following statements is true? a. Nonparametric methods can be applied to a wider variety of problems because they have more rigid

requirements than parametric methods. b. Nonparametric methods can be applied to a wider variety of problems because they have less rigid requirements than parametric methods. c. Unlike parametric methods, nonparametric methods cannot be applied to nominal data that lack numeric values. d. Nonparametric methods can be applied to a wider variety of problems because they have less rigid requirements than parametric methods and unlike parametric methods, nonparametric methods cannot be applied to nominal data that lack numeric values. e. None of these. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 30. Consider the following data set: 14, 14, 15, 16, 18, 19, 19, 20, 21, 22, 23, 25, 25, 25, 25, and 28. The rank

assigned to the four observations of value 25 is: a. 12 b. 12.5 c. 13 d. 13.5 e. 14 ANSWER:

Chapter 15 - Nonparametric Statistics POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 31. Which of the following statements about nonparametric tests is false? a. We can safely employ nonparametric tests even when we know nothing at all about the populations

from which sample data are being drawn. b. We can conduct nonparametric tests with nominal data. c. We can conduct nonparametric tests with ordinal data. d. We can only conduct nonparametric tests with data of a higher order than nominal or ordinal. e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 32. Which of the following statements is false? a. We can conduct nonparametric tests even with nominal and ordinal data. b. When parametric assumptions are valid and, therefore, either type of test could be used.

Nonparametric tests are less powerful than parametric tests. c. Given sample size and specified significance level , the probability of a Type II error is smaller for a nonparametric test. d. Using a nonparametric test when we could employ a parametric test can be less efficient: A nonparametric test often tends to ignore available sample information-for example, by focusing only on the directions rather than the sizes of observed differences. e. None of these. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 4/15/2019 4:30 AM 33. Which of the following correctly describes the Wilcoxon rank-sum test? a. It is a nonparametric test based on two independent simple random samples. b. It is designed to determine whether the relative frequency distributions of two statistical populations

of continuous values are identical to or different from one another. c. The Wilcoxon rank-sum test is equivalent to a parametric t-test of the difference between means of

Chapter 15 - Nonparametric Statistics

two independent samples. d. All of the above. e. None of the above. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 4/15/2019 4:38 AM 34. Comparing the output of strawberries grown on plots using fertilizer A with that grown on otherwise

identical plots using fertilizer B and with that grown on otherwise identical plots using fertilizer C, in order to make a general assessment of relative fertilizer effectiveness, may well call for: a. a Friedman-Smirnov test b. a Kruskal-Wallis test c. a Wilcoxon rank-sum test d. a Spearman rank correlation test e. a chi-square test ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 4/15/2019 4:48 AM 35. When assigning ranks during a Wilcoxon rank-sum test, tied observations are assigned the average of the

ranks that the observations would have had if they had been slightly different in value. Which of the following statements about this averaging procedure is false? a. The procedure is crucial when the tied values belong to the same sample. b. Although still employed, the procedure is not crucial (and an arbitrary assignment of ranks to tied

values would be acceptable) when the tied values belong to the same sample. c. The procedure is designed to avoid arbitrariness. [In the absence of this procedure, depending on whether one rank (say, 4) was assigned to sample 1 figure and the next rank (say, 5) to sample 2 or whether rank 5 went to sample figure and 4 to sample 2, we would produce a different sum of ranks for the two samples.] d. Although still employed, the procedure is not crucial (and an arbitrary assignment of ranks to tied values would be acceptable) when the tied values belong to the same sample and the procedure is designed to avoid arbitrariness. [In the absence of this procedure, depending on whether one rank (say, 4) was assigned to sample 1 figure and the next rank (say, 5) to sample 2 or whether rank 5 went to sample figure and 4 to sample 2, we would produce a different sum of ranks for the two samples.] e. They are all false. ANSWER:

Chapter 15 - Nonparametric Statistics POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 4/15/2019 5:56 AM 36. You are performing the Wilcoxon rank-sum test. The 14th through 16th values in an ordered array of pooled

sample data all equal $160 (while the 13th value is less and the 17th value is more). The appropriate ranks for the three $160 values are: a. 14, 15, 16 b. 15, 15, 15 c. 13.5, 14, 15.5 d. 14.5, 15, 16.5 e. 14, 14, 14 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 37. To apply the Wilcoxon rank sum test to determine whether the location of population 1 is different from the

location of population 2, the samples must be: a. drawn from normal populations b. drawn from matched pairs experiment c. independent d. larger than 30 e. larger than 50 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 38. A Wilcoxon rank sum test for comparing two populations involves two independent samples of sizes 5 and

7. The alternative hypothesis is stated as: The location of population 1 is different from the location of population 2. The appropriate critical value at the 5% significance level is: a. 20 b. 21 c. 18 d. 35

Chapter 15 - Nonparametric Statistics e. 38 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 4/15/2019 6:04 AM 39. The Wilcoxon rank sum test statistic T is approximately normally distributed whenever the sample sizes are

larger than or equal to: a. 10 b. 15 c. 20 d. 25 e. 30 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 40. Consider the following two independent samples:

Sample A: 16 17 19 22 47 Sample B: 27 31 34 37 40 The value of the test statistic for a left-tailed Wilcoxon rank sum test is: a. 6 b. 20 c. 35 d. 55 e. 70 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 41. A nonparametric method to compare two populations, when the samples are independent and where the

normality requirement necessary to perform the parametric test is not satisfied, is the:

Chapter 15 - Nonparametric Statistics a. Wilcoxon rank sum test b. sign test c. Wilcoxon signed rank sum test d. two-sample t-test of e. chi-square text ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 4/15/2019 6:17 AM 42. Statistical methods that require few assumptions, if any, about the population distribution are known as: a. parametric techniques b. nonparametric techniques c. free agent techniques d. all of these e. none of these ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 43. The nonparametric tests such as Wilcoxon rank sum test, sign test, Wilcoxon signed rank test, Kruskal-

Wallis test, and Friedman test all require that the probability distributions be: a. identical except with respect to location b. identical except with respect to spread (variance) c. identical except with respect to shape (distribution) d. different with respect to location, spread, and shape e. different with respect to location ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 4/15/2019 6:21 AM 44. Consider the following two independent samples:

Sample A: 15 17 18

Chapter 15 - Nonparametric Statistics

Sample B: 14 16 19 19 20 22 23 The value of the test statistic for a right-tailed Wilcoxon rank sum test is: a. 3 b. 7 c. 11 d. 22 e. 31 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 4/15/2019 6:29 AM 45. Statistical methods that require, among other assumptions, that the populations be normally distributed are

known as: a. distribution-free techniques b. nonparametric techniques c. parametric techniques d. distribution-free techniques and nonparametric techniques e. none of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 46. In a Wilcoxon rank sum test, the two sample sizes are 4 and 6, and the value of the Wilcoxon test statistic is

T = 20. If the test is a two-tailed and the level of significance is , then: a. the null hypothesis will be rejected b. the null hypothesis will not be rejected c. the alternative hypothesis will not be rejected d. the null hypothesis will be rejected and the alternative hypothesis will not be rejected e. not enough information has been given to answer this question ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM

Chapter 15 - Nonparametric Statistics 47. Comparing the output of strawberries with using three fertilizers A, B, C grown on three adjacent identical

plots on five different fields, in order to make a general assessment of relative fertilizer effectiveness, may well call for a: a. Friedman test b. Kruskal-Wallis test c. Wilcoxon rank-sum test d. Spearman rank correlation test e. chi-square test ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 4/23/2019 2:45 AM 48. A Wilcoxon rank sum test for comparing two populations involves two independent samples of sizes 15 and

20. The un-standardized test statistic (that is the rank sum) is T = 210. The value of the standardized test statistic z is: a. 14.0 b. 10.5 c. 6.0 d. -2.0 e. -3.2 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 49. You are performing the Wilcoxon rank-sum test. The 13th through 15th values in an ordered array of pooled

sample data all equal $180 (while the 12th value is less and the 16th value is more). The appropriate ranks for the three $180 values are: a. 13, 14, 15 b. 14, 14, 14 c. 12.5, 13, 14.5 d. 12.5, 13, 15 e. 13, 13, 13 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False

Chapter 15 - Nonparametric Statistics DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 50. In a normal approximation to the Wilcoxon rank sum test, the standardized test statistic is calculated as z =

1.80. For a two-tail test, the p-value is: a. 0.0359 b. 0.4641 c. 0.2321 d. 0.0718 e. 0.0528 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 51. Which of the following will never be a required condition of a nonparametric test? a. The samples are drawn from normally distributed populations. b. The samples are drawn from abnormally distributed populations. c. The populations being compared are identical in spread and shape. d. All of the above. e. None of the above. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 4/15/2019 6:55 AM 52. A nonparametric method that is equivalent to the Wilcoxon rank sum test is the: a. Wilcoxon signed rank sum test b. Friedman test c. Kruskal-Wallis test d. Mann-Whitney test e. chi-square test ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM

Chapter 15 - Nonparametric Statistics 53. Consider the following data set: 2.2, 2.3, 2.3, 2.5, 2.6, 2.7, 2.8, 2.8, 2.8, 2.9, 3.1, 3.2, and 3.5. The rank

assigned to the three observations of value 2.8 is: a. 6 b. 7 c. 8 d. 9 e. 10 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 54. The first step in a Wilcoxon rank sum test is to combine the data values in the two samples and assign a rank

of 1 to the: a. smallest observation b. middle observation c. largest observation d. observation that occurs most frequently e. observation that occurs least frequently ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 55. The Wilcoxon rank sum test actually tests to determine whether the population distributions have: a. identical locations b. identical spreads (variances) c. identical shapes d. all of these e. none of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 4/16/2019 3:04 AM 56. What is the test statistic for a right-tailed test in the Wilcoxon rank sum procedure? Suppose that

independent random samples

Chapter 15 - Nonparametric Statistics

of size n1 and n2 are selected from populations 1 and 2, respectively. Let n1 represent the smaller of the two sample sizes, and let T1 represent the sum of the ranks of the observations in sample 1. a. T1 b. T1* = n1(n1 + n2 + 1) – T1 c. n1 + n2 d. minimum of T1 and T1* e. T2 = rank sum for the observations in sample 2 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 4/23/2019 2:44 AM 57. To use the Wilcoxon Rank Sum Test as a test for location, we must assume that: a. the obtained data are either ordinal or interval where the normality requirement necessary to perform

the two-sample t-test of

is unsatisfied

b. both samples are randomly and independently drawn from their respective populations c. both underlying populations from which the samples were drawn are equivalent in shape and

dispersion d. all of these e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 4/16/2019 3:15 AM 58. Which of the following correctly describes the Mann–Whitney U-test? a. It is a nonparametric test based on two independent simple random samples. b. It is designed to determine whether the relative frequency distributions of two statistical populations

of continuous values are identical to or different from one another. c. It is equivalent to a parametric t-test of the difference between two means. d. All of these. e. None of these. ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice

Chapter 15 - Nonparametric Statistics HAS VARIABLES: False DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 4/16/2019 3:27 AM 59. To investigate the effect of sleep on basal metabolism, seven college students who averaged seven or more

hours of sleep a night (Group A), and five students who averaged less than seven hours of sleep a night (Group B), were examined and their basal metabolism recorded as shown below.

Since it was not clear whether the assumptions for a t-test were valid, the researcher decided to employ nonparametric methods. Use the Wilcoxon rank sum procedure to determine whether the metabolism measurements for Group A are significantly higher than those of Group B. Use = 0.05. The null and alternate hypotheses are as follows: : The distributions of metabolism measurements for the two groups are identical. : The distribution of metabolism measurements for Group B is shifted to the left of Group A. (i.e., the metabolism measurements are lower for Group B) What is the test statistic?

: What is the critical value for the test statistic?

Thus: Conclude:

We for Group A. ANSWER:

conclude the distribution of metabolism measurements for Group B is lower than those 24.5; 21; Fail to reject the null hypothesis; cannot

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic 2/4/2019 9:48 AM DATE CREATED: DATE MODIFIED: 2/4/2019 9:48 AM

Chapter 15 - Nonparametric Statistics 60. A vendor was interested in determining whether two soft drink machines dispense the same amount of

liquid. A sample of size seven was selected from each machine and the amount of liquid dispensed (in ounces) was recorded as

Use the Wilcoxon rank sum test to determine whether the distributions for the amount of liquid dispensed are the same for both machines. Use = 0.05. The null and alternate hypotheses are: : The distributions for the amount of liquid dispensed are identical for the two machines. : The distributions for the amount of liquid dispensed differ for the two machines. What is the test statistic?

T: What is the critical value for the test statistic?

Thus: Conclude:

We conclude that the distributions of the amount of liquid dispensed by the two machines are ANSWER: 43; 39; Fail to reject the null hypothesis; identical POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic 2/4/2019 9:48 AM DATE CREATED: DATE MODIFIED: 2/4/2019 9:48 AM

Chapter 15 - Nonparametric Statistics 61. Suppose you want to use the Wilcoxon rank sum test to detect a shift in distribution 1 to the right of

distribution 2, based on samples of sizes

= 7 and

= 9.

Should you use T1 or T1* as the test statistic?

What is the rejection region for the test if = 0.05?

Reject

if the test statistic

What is the rejection region for the test if = 0.01?

Reject

if the test statistic

ANSWER:

. T1*; 43; 37

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 62. In an investigation of the visual scanning behavior of deaf children, measurements of eye movement rates

were taken on nine deaf and nine hearing children as shown in the table below.

Does it appear that the distributions of eye-movement rates for deaf children and hearing children differ? Test at = 0.05 using the Wilcoxon rank sum test. The null and alternate hypotheses are: : The distributions of eye-movement rates for hearing impaired children and hearing children are identical. : The distributions of eye-movement rates for hearing impaired children and hearing children are different.

Chapter 15 - Nonparametric Statistics

What is the test statistic?

T: What is the critical value for the test statistic?

Thus: Conclude:

We conclude that the hearing impaired children from the hearing children in eye-movement rate. ANSWER: 45; 62; Reject the null hypothesis; differ POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 63. Suppose you want to use the Wilcoxon rank sum test to detect a shift in distribution 1 either to the left or to

the right of distribution 2, based on samples of sizes Should you use T1 or T1* as the test statistic?

What is the rejection region for the test is = 0.05?

Reject

if the test statistic

What is the rejection region for the test if =0.01?

Reject

if the test statistic

ANSWER:

. T=min(T1,T1*); 43; 37

POINTS: QUESTION TYPE:

1 Subjective Short Answer

= 7 and

= 9.

Chapter 15 - Nonparametric Statistics HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 64. Use the Wilcoxon rank sum test on the data below to determine at the 10% significance level whether the

two population locations differ.

The null and alternate hypotheses are: : The two population locations are the same. : The two population locations are different. Test statistic = Critical Value = Conclusion: The two population locations are _. ANSWER: 90.5; 82; Fail to reject the null hypothesis; the same POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 4/16/2019 3:49 AM 65. In testing the hypotheses:

H0: The two population locations are the same. H1: The two population locations are different. The statistics n1 = 5, n2 = 9, T1 = 22, and T1* = 53 are calculated with data drawn from two independent samples. What is the value of the test statistic?

Test statistic =

Chapter 15 - Nonparametric Statistics

What is the rejection region for this test at = 0.05?

Critical Value = What is your conclusion at = 0.05?

Conclusion:

The two population locations are _. ANSWER: 22; 22; Reject the null hypothesis; different POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 2/4/2019 9:48 AM 66. The following statistics are drawn from two independent samples: n1 = 25, n2 = 28, T1 = 800, and T1* = 550.

Test at the 5% significance level to determine whether the two population locations differ. The null and alternate hypotheses are: : The two population locations are the same. : The two population locations differ. Test statistic =

Round your answer to three decimal places.

Critical Value =

Round your answer to two decimal places.

Conclusion: The two population locations are _. ANSWER: 2.227; 1.96; Reject the null hypothesis; different POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 4/16/2019 4:01 AM 67. Given the statistics: n1 = 6, n2 = 9, T1 = 42, and T1* = 54, use the Wilcoxon rank sum test to determine at the

5% significance whether the location of population 1 is to the left of the location of population 2.

Chapter 15 - Nonparametric Statistics

The null and alternate hypotheses are: : The two population locations are the same. : The location of population 1 is to the left of the location of population 2. Test statistic = Critical Value = Conclusion: The two population locations are _. ANSWER: 42; 33; Fail to reject the null hypothesis; the same POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 4/16/2019 4:56 AM 68. Because of the rising costs of industrial accidents, many chemical, mining, and manufacturing firms have

instituted safety courses. Employees are encouraged to take these courses designed to heighten safety awareness. A company is trying to decide which one of two courses to institute. To help make a decision, eight employees take course 1 and another eight take course 2. Each employee writes a test, which is marked, out of a possible 25. The results are shown below.

Do these data provide sufficient evidence at the 5% level of significance to conclude that the marks from course 2 are higher than those of course 1? Assume that the scores are not normally distributed. The null and alternate hypotheses are: : The two population locations are the same. : The location of population 1 (course 1) is to the left of the location of population 2. Test statistic =

Chapter 15 - Nonparametric Statistics

Critical Value = Conclusion: There ANSWER:

enough evidence to include conclude that the two populations are the same. 55.5; 51; Fail to reject the null hypothesis; is not

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 4/16/2019 5:28 AM 69. In testing the hypotheses:

H0: The two population locations are the same. H1: The location of population 1 is to the left of the location of population 2. The statistics n1 = 6, n2 = 8, T1 = 32, and T1* = 58 are calculated with data drawn from two independent samples. What is the value of the test statistic? Test statistic = What is the rejection region for this test at = 0.05? Critical Value = What is your conclusion at = 0.05? Conclusion: There ANSWER:

enough evidence to include conclude that the two populations are the same. 32; 31; Fail to reject the null hypothesis; is not

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 4/16/2019 5:29 AM 70. Use the Wilcoxon rank sum test on the data below to determine at the 10% significance level whether the

two population locations differ.

Chapter 15 - Nonparametric Statistics

The null and alternate hypotheses are: : The two population locations are the same. : The two population locations are different. Test statistic = Critical Value = Conclusion: There ANSWER:

enough evidence to include conclude that the two populations are the same. 34; 29; Fail to reject the null hypothesis; is not

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:48 AM DATE MODIFIED: 4/16/2019 5:41 AM 71. When the direction (and not the magnitude) of the difference within each matched paired in a paired

experiment is known, the sign test can be used while the Wilcoxon Signed-Rank test cannot be used. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 72. The Sign test or Wilcoxon Signed-Rank test are nonparametric tests that can be used to compare two

dependent samples when the assumptions for a t-test are invalid. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM

Chapter 15 - Nonparametric Statistics 73. The sign test is always to be preferred to the t test. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 74. In a normal approximation to the sign test, the standardized test statistic is calculated as z = 2.17. If the

alternative hypothesis states that the location of population 1 is to the right of the location of population 2, then the p-value of the test is 0.015. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 75. The sign test is employed to compare two populations when the experimental design is matched pairs, and

the data are ordinal but not normally distributed. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 76. One of the required conditions of the sign test is that the number of nonzero differences n must be greater

than or equal to 30. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM

Chapter 15 - Nonparametric Statistics 77. The sign test is a nonparametric test that 1) uses the directions of differences observed in a matched pairs

Chapter 15 - Nonparametric Statistics

sample to determine whether the relative frequency distributions of two statistical populations are identical to or different from one another and 2) determines whether a sample comes from a population with a specified median. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 78. The sign test is a nonparametric procedure for testing: a. whether two populations have identical means b. whether two populations have identical medians c. whether two populations have identical probability distributions d. the amount of skewness in a single population e. none of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 79. Which one of the following is not a reason why one might use a sign test to make a comparison between two

populations? a. Some studies yield responses which are difficult to quantify. b. It is easy to use the sign-testing procedure. c. The data in question consist of count data. d. No assumptions need to be made about the form of the population probability distributions. e. Some studies yield responses which are difficult to quantify and the data in question consist of count data. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 80. In the case of the sign test, the null hypothesis is of the form: a. there is a difference in the probability distribution for the two populations b. there is no difference in the probability distribution for the two populations

Chapter 15 - Nonparametric Statistics c. the two populations in questions are both normally distributed d. e. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 81. Which one of the following is a correct statement about the sign test? a. Tied pairs are considered in the analysis. b. Only the signs of the differences and not the actual values are used in the analysis. c. Its inability to cope with small samples. d. All of the above. e. None of the above. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/16/2019 6:50 AM 82. A nonparametric method to compare two populations, when the samples are matched pairs and the data are

ordinal, is the: a. Wilcoxon signed rank sum test b. sign test c. Wilcoxon rank sum test d. matched pairs t-test e. chi-square test ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 83. In a normal approximation to the sign test, the standardized test statistic is calculated as z = -1.58. To test the

alternative hypothesis that the location of population 1 is to left of the location of population 2, the p-value of the test is: a. 0.1142 b. 0.2215 c. 0.0571

Chapter 15 - Nonparametric Statistics d. 0.2284 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 84. In the sign test applications, the normal approximation to the binomial distribution works very well even

when the number of nonzero differences is as small as: a. 5 b. 10 c. 15 d. 25 e. 30 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 85. Which of the following correctly describes the sign test? a. It often uses the directions of differences observed in matched-pairs sample to determine whether the

relative frequency distributions of two statistical populations are identical to or different from one another. b. It is often used to determine whether a sample comes from a population with a specified median. c. It is often used to determine whether a sample comes from a population with a specified mean. d. Both it often uses the directions of differences observed in matched-pairs sample to determine whether the relative frequency distributions of two statistical populations are identical to or different from one another and it is often used to determine whether a sample comes from a population with a specified median. e. Neither it often uses the directions of differences observed in matched-pairs sample to determine whether the relative frequency distributions of two statistical populations are identical to or different from one another nor it is often used to determine whether a sample comes from a population with a specified median. ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/23/2019 2:49 AM

Chapter 15 - Nonparametric Statistics 86. Twenty students are given an attitude test before and after viewing a motion picture designed to change their

attitudes favorably toward a new curriculum. A high score indicates a favorable attitude and a low score indicates an unfavorable attitude, with the scores ranging from 1 to 30. This problem will use the sign test on the data given below to see if we can conclude the motion picture was successful in improving attitudes.

Describe what the test statistic is for the sign test.

What is the value of the test statistic in this problem?

Is this a one-tailed test or a two-tailed test?

Find the rejection region for = 0.10. Reject

when T >

Using

as above, can we conclude the motion picture was successful in changing attitudes?

Conclusion: There

enough evidence to conclude that two populations are different.

At what level of significance could we reject H0? Round your answer to three decimal places.

ANSWER:

Let x be the number of times the "After" measurement was larger than the "Before" measurement; that is, number of times where (After - Before) is positive.; 13; onetailed; 13; Fail to reject the null hypothesis; is not; .132

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM

Chapter 15 - Nonparametric Statistics DATE MODIFIED:

4/17/2019 3:05 AM

87. A car dealer was interested in comparing two brands of tires to see if they yielded different wear length (in

thousands of miles). The dealer selected eight cars at random and used each of the brands of tires on each car. The wear length was recorded as follows:

Use the sign test to see if the distribution of wear length is the same for both brands of tires. Use = 0.05. The null and alternate hypotheses are: : The distributions of wear length are identical for the two brands of tires, and P(A exceeds B) = p = 0.50. : The distributions of wear length are not identical for the two brands of tires, and p 0.50. What is the test statistic? x= What is the p-value for the test statistic? Round your answer to three decimal places.

Conclusion Conclude that the distributions of wear length for the two brands of tires are ANSWER: 3; .726; Fail to reject the null hypothesis; identical

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/17/2019 3:30 AM 88. A dog kennel manager was interested in determining whether there is a difference in the time it takes a dog

to complete an obstacle course for two different courses. A random sample of 36 dogs was selected and the time it took each dog to complete each course was recorded. In twelve cases it took the dog longer to complete course #1. Use the normal approximation to the sign test to determine if there is a significant difference in the time it takes to complete the two obstacle courses. Use = 0.05.

Chapter 15 - Nonparametric Statistics

The null and alternate hypotheses are: : The distributions of completion time for an obstacle course are identical for the two different courses, and p = 0.50. : The distributions of completion time for an obstacle course are not identical for the two different courses, and p 0.50. What is the z-statistic? Round your answer to one decimal place.

What is the critical value for the test statistic? Round your answer to two decimal places. Reject

if |z| >

Conclude that the distributions of completion time for an obstacle course are different courses. ANSWER: -2.0; 1.96; Reject the null hypothesis; different

for the two

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/17/2019 3:39 AM 89. A paired-difference experiment was conducted to compare two populations. The data are shown in the table.

Use a sign test to determine whether the population distributions are different. Population

9.6

8.8

10.0

8.4

11.1

9.0

8.1

9.5

8.1

9.7

8.5

10.6

8.8

7.6

The null and alternate hypotheses are as

follows: H0: The two population distributions are identical and P(A exceeds B) = p = 0.5 Ha: The population distributions are not identical and p ≠ 0.5 Determine an appropriate rejection region with Critical Values:

Enter n1, n2

Calculate the observed value of the test statistic.

0.01.

Chapter 15 - Nonparametric Statistics

Conclude: The data present ANSWER:

evidence to indicate that populations A and B are different. 0,7; 6; Do not reject the null hypothesis; insufficient

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/17/2019 4:07 AM 90. Two gourmets, A and B, rated 22 meals on a scale of 1 to 10. The data are shown in the table. Do the data

provide sufficient evidence to indicate that one of the gourmets tends to give higher ratings than the other?

Test by using the sign test with a value of near 0.05. The null and alternate hypotheses are as follows: H0: The two population distributions are identical and P(A exceeds B) = p = 0.5 Ha: The population distributions are not identical and p ≠ 0.5 Critical Value approach: What is the test statistic?

Use the binomial tables to find the exact rejection region for the test. Reject

if x

Conclude:

or x

Chapter 15 - Nonparametric Statistics

There

enough evidence to indicate a difference between the two gourmets.

p-value approach: Test Statistic:

p-value =

Round your answer to three decimal places.

Conclude:

There is

_ enough evidence to indicate a difference between the two gourmets.

Use the large-sample z statistic for testing. (NOTE: Although the large-sample Approximation is suggested for 25, it works fairly well for values of n as small as 10.) The large sample z-statistic is: Round your answer to two decimal places. The two-tailed rejection region is |z| >

Conclude:

There is

_ enough evidence to indicate a difference between the two gourmets.

Compare the results of the two tests. The two tests give ANSWER:

results. 11; 5; 15; Do not reject the null hypothesis; is not; 11; .824; Do not reject the null hypothesis; is not; .45; 1.96; Do not reject the null hypothesis; is not; the same

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/17/2019 4:51 AM

Chapter 15 - Nonparametric Statistics 91. It is important to sponsors of television shows that viewers remember as much as possible about the

commercials. The advertising executive of a large company is trying to decide which of two commercials to use on a weekly half-hour comedy. To help make a decision she decides to have 12 individuals watch both commercials. After each viewing, each respondent is given a quiz consisting of 10 questions. The number of correct responses is recorded and listed below. Assume that the quiz results are not normally distributed.

Do these data provide enough evidence at the 5% significance level to conclude that the two commercials differ? (NOTE: Although the large-sample Approximation is suggested for n ≥ 25, it works fairly well for values of n as small as 10.) z-statistic = Reject

if |z| >

Round your answer to two decimal places. Round your answer to two decimal places.

Conclusion: The data differ ANSWER:

_ enough evidence at the 5% significance level to conclude that the two commercials –2.53; 1.96; Reject the null hypothesis; provide

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/17/2019 5:55 AM 92. Ten secretaries were selected at random from among the secretaries of a large university. The typing speed

(number of words per minute) was recorded for each secretary on two different brands of computer keyboards. Assume that the typing speeds are not normally distributed. The following results were obtained.

Chapter 15 - Nonparametric Statistics

Test to determine if these data provide enough evidence at the 5% significance level to infer that the brands differ with respect to typing speed. (NOTE: Although the large-sample Approximation is suggested for n ≥ 25, it works fairly well for values of n as small as 10.) z-statistic = Reject

if |z| >

Round your answer to two decimal places. Round your answer to two decimal places.

Conclusion: These data respect to typing speed.

enough evidence at the 5% significance level to infer that the brands differ with

ANSWER:

.63; 1.96; Fail to reject the null hypothesis; don't provide

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/17/2019 6:02 AM 93. In general, before an academic publisher agrees to publish a book, each manuscript is thoroughly reviewed

by university professors. Suppose that the Duxbury Publishing Company has recently received two manuscripts for statistics books. To help them decide which one to publish both are sent to 30 professors of statistics who rate the manuscripts to judge which one is better. Suppose that 10 Professors rate manuscript 1 better and 20 rate manuscript 2 better. Can Duxbury conclude at the 5% significance level that manuscript 2 is more highly rated than manuscript 1? z-statistic = Reject

if z <

Conclusion:

Round your answer to two decimal places. Round your answer to two decimal places.

Chapter 15 - Nonparametric Statistics

Duxbury manuscript 1.

conclude at the 5% significance level that manuscript 2 is more highly rated than

What is the p-value of the test you just conducted? Round your answer to four decimal places.

ANSWER:

–1.83; –1.64; Reject the null hypothesis; can; .0336

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/17/2019 6:12 AM 94. A supermarket chain has its own house brand of ice cream. The general manager claims that her ice cream is

better than the ice cream sold by a well-known ice cream parlor chain. To test the claim 40 individuals are randomly selected to participate in the following experiment. Each respondent is given the two brands of ice cream to taste (without any identification) and asked to judge which one is better. Suppose that 25 people judge the ice cream parlor brand better, five say that the brands taste the same, and the rest claim that the supermarket brand is better. Can we conclude at the 1% significance level that the general managers' claim is false? Test statistic: z-statistic =

Round your answer to two decimal places.

Rejection region: Reject

if the z-statistic ................................. Round your answer to two decimal places.

Conclusion: We

conclude at the 1% significance level that the general managers' claim is false.

What is the p-value for the above test? Round your answer to four decimal places.

ANSWER:

–2.54; –2.33; Reject the null hypothesis; can; .0055

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/17/2019 6:47 AM 95. A matched pairs experiment yielded the following results:

Chapter 15 - Nonparametric Statistics

Number of positive differences = 20, Number of negative differences = 8 Number of zero differences = 2 Can we infer at the 5% significance level that the location of population 1 is to the right of the location of population 2? Test statistic: z-statistic =

Round your answer to two decimal places.

Rejection region: Reject

if the z-statistic

. Round your answer to three decimal places.

Conclusion: We infer at the 5% significance level that the location of population 1 is to the right of the location of population 2. ANSWER: 2.27; 1.645; Reject the null hypothesis; can POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/17/2019 6:49 AM 96. The critical value is taken from the F-distribution whenever the Wilcoxon signed rank test is employed. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 97. The Wilcoxon signed rank test is a nonparametric test that uses the directions of differences observed in a

matched-pairs sample to determine whether the relative frequency distributions of two statistical populations are identical to or different from one another. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False

Chapter 15 - Nonparametric Statistics HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 98. A t-test for two independent samples corresponds to a Wilcoxon signed rank test for paired samples. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/17/2019 6:56 AM 99. The Wilcoxon signed-rank test is a nonparametric test that 1) uses the directions of differences observed in a

matched pairs sample to determine whether the relative frequency distributions of two statistical populations are identical to or different from one another and 2) determines whether a sample comes from a population with a specified median. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 100. A one-sample t-test is the parametric counterpart of the Wilcoxon signed rank test for matched pairs. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 101. The Wilcoxon signed rank test for matched pairs is the nonparametric counterpart of the paired two-sample a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False

Chapter 15 - Nonparametric Statistics

t-test of

a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False

Chapter 15 - Nonparametric Statistics HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 102. The null hypothesis for the Wilcoxon signed rank test is the distributions for populations 1 and 2 are

identical. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/18/2019 4:22 AM 103. The z-test approximation to the Wilcoxon signed rank sum test is used whenever the number of non-zeros

differences is at least 50. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 104. Which of the following tests employs matched-pairs sampling? a. The Wilcoxon signed-rank test b. The Wilcoxon rank-sum test c. The Mann-Whitney test d. The Friedman test e. The chi-square test ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/23/2019 2:52 AM 105. The Wilcoxon Signed-Rank test: a. makes use of the sign of the differences between pairs of measurements and the rank of the absolute values of the differences b. is concerned with the analysis of a single population

Chapter 15 - Nonparametric Statistics c. cannot cope with ordinal data d. makes use of the sign but does not consider the magnitude of the differences between pairs of

measurements. e. cannot cope with ordinal data and makes use of the sign but does not consider the magnitude of the differences between pairs of measurements ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/17/2019 7:30 AM 106. In the Wilcoxon Signed-Rank test, if two or more measurements have the same nonzero difference, signs

ignored, then: a. the tied observations are eliminated from the analysis b. the tied observations are assigned the lowest rank of the ranks that would have been assigned with no

ties c. the tied observations are assigned the highest rank of the ranks that would have been assigned with no ties d. the tied observations are assigned the average of the ranks that would have been assigned with no ties e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/17/2019 7:45 AM 107. The Wilcoxon Signed-Rank test may be more appropriate than the paired-difference t-test if: a. the population of differences is not normal b. the population of differences is normal c. the sample size is small d. the data values are quantitative e. the sample size is small or the population of differences is not normal ANSWER: e POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/17/2019 7:49 AM 108. A paired sample, two-sample t-test, corresponds to:

Chapter 15 - Nonparametric Statistics a. a Wilcoxon signed rank test for paired samples b. a Wilcoxon rank sum test c. a Wilcoxon signed rank test for one sample d. a Friedman test for randomized block design e. none of these ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 109. The Wilcoxon signed-rank test involves: a. calculating the difference between the sample data for each matched pair. (Pairs with zero differences

are eliminated from the test at this stage, and sample size, n, is reduced to the remaining number of pairs with nonzero differences) b. ranking the absolute values of the (nonzero) differences from the smallest (rank= 1 ) to the largest (rank = n) c. attaching to each rank the sign of the original difference corresponding to it, calculating the sum of these signed ranks, and designating it as the test statistic, T d. all of these e. none of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/17/2019 7:50 AM 110. What is the test statistic for a two-tailed test in the Wilcoxon signed-rank procedure? a. T = the smaller of the rank sum for positive and the rank sum for negative differences b. T – = the rank sum for negative differences c. T + = the rank sum for negative differences d. T = the larger of the rank sum for positive and the rank sum for negative differences e. T + + T – ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/23/2019 3:14 AM

Chapter 15 - Nonparametric Statistics 111. The Wilcoxon signed rank test statistic is approximately normally distributed when the null hypothesis is

true and the sample size is larger than or equal to: a. 10 b. 20 c. 25 d. 35 e. 45 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/17/2019 8:09 AM 112. The significance level for a Wilcoxon signed rank test is 0.05. The alternative hypothesis is stated as: The

location of population 1 is different from the location of population 2. The appropriate critical value for a sample of size 20 (that is the number of nonzero differences is 20) is: a. 37 b. 43 c. 52 d. 60 e. 48 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/17/2019 7:59 AM 113. The significance level for a Wilcoxon signed rank test is 0.05. The alternative hypothesis is stated as: The

location of population 1 is to the left of the location of population 2. The appropriate critical value for a sample of size 20 (that is the number of nonzero differences) is: a. 37 b. 43 c. 52 d. 60 e. 70 ANSWER:

POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False

Chapter 15 - Nonparametric Statistics DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 114. In a normal approximation to the Wilcoxon signed rank test, the test statistic is calculated as z = 1.36. For a

two-tail test, the p-value is: a. 0.1738 b. 0.2066 c. 0.0869 d. 0.4131 e. 0.3518 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 115. The significance level for a Wilcoxon signed rank test is 0.05. The alternative hypothesis is stated as: The

location of population 1 is to the left of the location of population 2. The appropriate critical value for a sample of size 25 (that is, the number of nonzero differences is 25) is: a. 68 b. 77 c. 90 d. 101 e. 112 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 116. In a Wilcoxon signed rank test for matched pairs with n = 35, the rank sums of the positive and negative

differences are 380 and 250, respectively. The value of the standardized test statistic z is: a. 1.689 b. 1.065 c. 1.206 d. 1.400 e. 1.510 ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False

Chapter 15 - Nonparametric Statistics DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/18/2019 2:33 AM 117. The nonparametric counterpart of the parametric t-test of a. Friedman test

for matched pairs is the:

b. Kruskal-Wallis test c. Wilcoxon signed rank test d. Wilcoxon rank sum test e. chi-square test ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 118. A nonparametric method to compare two populations, when data are paired and come from the same

population, and where the normality requirement necessary to perform the parametric test is unsatisfied, is the: a. Wilcoxon rank sum test b. the goodness-of-fit test c. matched pairs t-test d. Wilcoxon signed rank test e. matched pairs z-test ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/18/2019 4:17 AM 119. In a Wilcoxon signed rank test for matched pairs with n = 32, the rank sums of the positive and negative

differences are 367.5 and 160.5, respectively. The value of the standardized test statistic z is: a. 3.764 b. 1.882 c. 1.391 d. 1.935 e. 1.986 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM

Chapter 15 - Nonparametric Statistics DATE MODIFIED: 2/4/2019 9:49 AM 120. In a Wilcoxon signed rank test, the test statistic is calculated as T = 75. If there are n = 15 observations for

which the difference is not zero, and a two-tailed test is performed at the 5% significance level, then: a. reject the null hypothesis b. don't reject the null hypothesis c. the test results are inconclusive d. perform a parametric test e. perform a chi-square test ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 121. Two aptitude tests are currently being used to screen applicants for a certain position within a company.

The question arose as to whether the two tests are comparable, i.e., whether they yield the same results. Six applicants were selected at random to take both tests (in a random order). The following scores were recorded:

Use the Wilcoxon signed-rank test to determine whether there is a difference in scores between the two tests. Use = 0.10. What is the test statistic?

What is the critical value for the test statistic?

Conclude:

Chapter 15 - Nonparametric Statistics

We tests.

conclude there is a difference in the frequency distributions of scores for the two aptitude

ANSWER:

10; 2; Fail to reject the null hypothesis; cannot

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 122. Suppose you wish to detect a difference in the locations of two population distributions based on a paired-

difference experiment consisting of n = 35 pairs. Use the Wilcoxon Signed-Rank test. [NOTE: 1)/2] If

= n(n +

= 339, what are your conclusions?

Give the test statistic. T= Give the rejection region for the test for = 0.05. Reject

if T

Conclude: There is

_ of a difference between the two distributions.

Conduct the test using the large-sample z-test. Compute the z-statistic: Reject

Round your answer to three decimal places.

if |z| ≥

. Round your answer to two decimal places.

Conclude: There is

_ of a difference between the two distributions.

Compare your results with the nonparametric test results above.

ANSWER:

291; 195; Fail to reject the null hypothesis; no evidence; -.393; 1.96; Fail to reject the null hypothesis; no evidence; The two tests give the same results.

POINTS:

Chapter 15 - Nonparametric Statistics QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/18/2019 2:56 AM 123. Eight people were asked to perform a simple puzzle-assembly task under normal conditions and under

stressful conditions. During the stressful time, a mild shock was delivered to subjects 3 minutes after the start of the experiment and every 30 seconds thereafter until the task was completed. Blood pressure readings were taken under both conditions. The data in the table are the highest readings during the experiment.

Do the data present sufficient evidence to indicate higher blood pressure readings under stressful conditions? Analyze the data using the Wilcoxon signed-rank test for a paired experiment. Use α = 0.05. Test statistic: T= What is the critical value for the test statistic? Reject

if the test statistic <

Conclude: We ANSWER:

conclude that higher blood pressure readings occur during conditions of stress. 3.5; 4; Reject the null hypothesis; can

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/18/2019 3:00 AM 124. Given the statistics: T + = 520, T – = 755, and n = 50 from a matched pairs experiment, perform the Wilcoxon signed rank test to determine whether we can infer at the 5% significance level that the two population locations differ.

Chapter 15 - Nonparametric Statistics Test statistic: z-statistic =

Round your answer to two decimal places.

Rejection region: Reject

if |z| >

Round your answer to two decimal places.

Conclusion: We infer at the 5% significance level that the two population locations differ. ANSWER: -1.13; 1.96; Fail to reject the null hypothesis; can't POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/18/2019 3:09 AM 125. In testing the hypotheses

: The two population locations are the same. : The two population locations are different. The statistics T + = 238, T – = 582, and n = 40 are calculated with data drawn from a matched pairs experiment. Test statistic: z-statistic =

Round your answer to two decimal places.

What is the p-value of this test?

Can we infer at the 5% significance level that the population locations differ? Conclusion: We ANSWER:

infer at the 5% significance level that the population locations differ. -2.31; .0208; Reject the null hypothesis; can

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/18/2019 3:08 AM

Chapter 15 - Nonparametric Statistics 126. In testing the hypotheses

: The two population locations are the same. : The location of population A is to the right of the location of population B. The statistics T + = 271, T – = 107, and n = 27 are calculated with data drawn from a matched pairs experiment. Test statistic: z-statistic = p-value = Conclusion: We infer at the 1% significance level that the location of population A is to the right of the location of population B. ANSWER: 1.97; .0244; Fail to reject the null hypothesis; cannot POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/18/2019 3:11 AM 127. Kruskal-Wallis test is a nonparametric test that can be used to compare more than two independent samples

when the assumptions for an analysis of variance are invalid. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 128. A one-sample t-test corresponds to a Kruskal-Wallis test. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM

Chapter 15 - Nonparametric Statistics DATE MODIFIED: 2/4/2019 9:49 AM 129. The normal approximation to the Wilcoxon signed rank test is used whenever the number of none zero

differences is 50 or more. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/18/2019 3:19 AM 130. The Kruskal-Wallis H test is an extension of the Wilcoxon rank-sum test from two to more than two

statistical populations. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 131. The Kruskal-Wallis test can be conducted as one or two-tail test. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 132. A one-sample t-test is the parametric counterpart of the Kruskal-Wallis test. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM

Chapter 15 - Nonparametric Statistics 133. The Kruskal–Wallis H-test is a valuable alternative to a one-way analysis of variance when the normality

Chapter 15 - Nonparametric Statistics

and equality of variance assumptions are violated. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/18/2019 3:32 AM 134. The Wilcoxon rank-sum test is applied to compare two or more populations, when the samples are

independent of equal or different sample sizes. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/18/2019 4:46 AM 135. The critical value is taken from the F-distribution whenever the test is a Kruskal-Wallis test. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 136. In a Kruskal-Wallis test, there are five samples, and the value of the test statistic is calculated as H = 12.32.

Then the most accurate statement that can be made about the p-value of the test is that it is greater than 0.025 but smaller than 0.05. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 137. In a Kruskal-Wallis test, there are three samples, and the value of the test statistic is calculated as H =

Chapter 15 - Nonparametric Statistics

7.378. Then the p-value of the test is 0.025.

Chapter 15 - Nonparametric Statistics a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 138. The Kruskal-Wallis test can be used to test for a difference between two populations. It will produce the

same outcome as the two-tail Wilcoxon rank sum test. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 139. In a Kruskal-Wallis test, there are four samples, and the value of the test statistic is calculated as H = 13.21.

Then the most accurate statement that can be made about the p-value of the test is that it is greater than 0.005 but smaller than 0.01. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 140. The Kruskal-Wallis test can be used to determine whether a difference exists between two populations.

However, to determine whether one population location is larger than another, we must apply the Wilcoxon rank sum test. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM

Chapter 15 - Nonparametric Statistics 141. In all applications of the Kruskal-Wallis test, the alternative hypothesis to be tested is always stated as:

Chapter 15 - Nonparametric Statistics a. the locations of all k populations are the same b. at least two population locations differ c. the locations of all w populations differ d. the locations of all k populations differ e. at least two population locations are the same ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 142. The Kruskal-Wallis Test for Differences in more than 2 Medians is a nonparametric alternative to: a. ANOVA F test for completely randomized experiments b. Student's t-test for related samples c. Student's t-test for independent samples d. Wilcoxon's Rank Sum Test for differences in two medians e. Student's t-test for related samples and Student's t-test for independent samples ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 143. In a Kruskal-Wallis test for comparing three populations, the test statistic is calculated as H = 2.80. If the

test is conducted at the 5% significance level, then: a. the null hypothesis will be rejected b. the null hypothesis will not be rejected c. the alternative hypothesis will not be rejected d. the test results are inconclusive e. the t-test for matched pairs must be used ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 144. The nonparametric counterpart of the parametric one-way analysis of variance F-test is the: a. Kruskal-Wallis test b. Friedman test c. Wilcoxon rank sum test

Chapter 15 - Nonparametric Statistics d. Wilcoxon signed rank sum test e. two-tailed t-test ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 145. The Kruskal-Wallis test is always: a. one-tail b. two-tail c. used with one sample d. used with only two samples e. used when the populations are normally distributed ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 146. In a Kruskal-Wallis test, there are four samples and the value of the test statistic is calculated as H = 8.79.

The most accurate statement that can be made about the p-value is that: a. it is greater than 0.10 b. it is greater than 0.05 but smaller than 0.10 c. it is greater than 0.05 d. it is greater than 0.025 but smaller than 0.05 e. it is less than 0.025 ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 147. A nonparametric method to compare two or more populations, when the samples are independent of equal

or different sample sizes but not normal, is the: a. Kruskal-Wallis test b. Friedman test c. Wilcoxon rank sum test d. Wilcoxon signed rank test

Chapter 15 - Nonparametric Statistics e. chi-square test ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/18/2019 4:48 AM 148. Suppose there is interest in comparing the median response time for three independent groups learning a

new specific task. The appropriate nonparametric procedure is: a. the Wilcoxon Rank Sums Test b. the Wilcoxon Signed Rank Test c. the Kruskal-Wallis Test for Differences in Medians d. the Friedman test e. none of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 149. Which of the following distributions approximate Kruskal-Wallis test statistic H when the problem

objective is to compare k distributions and the sample sizes are greater than or equal to 5? a. normal distribution b. chi-squared distribution with k - 1 degrees of freedom c. Student t-distribution with k - 2 degrees of freedom d. Student t-distribution with k - 3 degrees of freedom e. either chi-squared distribution with k - 5 degrees of freedom or Student t distribution with k + 5 degrees of freedom ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 150. The Kruskal-Wallis test statistic can be approximated by a chi-squared distribution with k - 1 degrees of

freedom (where k is the number of populations) whenever the sample sizes are all greater than or equal to: a. 5 b. 15 c. 25 d. 30

Chapter 15 - Nonparametric Statistics e. 45 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 151. Two different workbooks and two distinct teaching machines were to be evaluated on their effectiveness in

teaching the concept of multiplication. A fourth grade class of 24 subjects was randomly assigned to 4 groups and each group in turn was randomly assigned to a teaching method. A test was given and the number of errors was recorded. This problem uses the Kruskal-Wallis H test to see if the number of errors differs from one teaching method to another.

What is the value of H in this problem? Round your answer to three decimal places.

Find the rejection region for = 0.05. Round your answer to five decimal places. Reject

if H >

Conclude: There is method to another.

_ evidence at = 0.05 to say that the number of errors differs from one teaching

What is the p-value for this test?

ANSWER:

16.847; 7.81473; Reject the null hypothesis; sufficient; p-value

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 1:53 AM

Chapter 15 - Nonparametric Statistics 152. A computer laboratory manager was interested in whether there was a difference in functioning time before

needing to be recharged for three battery packs for laptop computers. The manager took a random sample of six battery packs of each brand and tested them. The results, in hours of functioning before needing to be recharged, were recorded as

The manager, unsure that the assumptions for the usual parametric analysis of variance were valid, decided to employ nonparametric methods. Use the appropriate nonparametric procedure to determine whether the distribution of functioning time before needing to be recharged is the same for the three brands of battery packs. Use = 0.05. Test Statistic: H=

Round your answer to three decimal places.

What is the critical value for the test statistic? Round your answer to five decimal places. Reject

if the test statistic >

Conclude: There sufficient evidence at = 0.05 to say that at least two of the distributions of functioning times before battery needing to be recharged differ in location. ANSWER: 12.117; 5.99147; Reject the null hypothesis; is POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 1:56 AM 153. Three treatments were compared using a completely randomized design. The data are shown in the table.

Chapter 15 - Nonparametric Statistics

Do the data provide sufficient evidence to indicate a difference in location for at least two of the population distributions? Test using the Kruskal-Wallis H statistic with = 0.05. Test statistic: H=

Round your answer to three decimal places.

What is the critical value for the test statistic? Reject

if the test statistic >

. Round your answer to five decimal places.

Conclude: There ANSWER:

a difference in location among the three treatments. 13.392; 5.99147; Reject the null hypothesis; is

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 2:02 AM 154. An experiment was conducted to examine the effect of age on heart rate when a person is subjected to a

specific amount of exercise. Ten men randomly selected from each of four age groups: 10-19, 20-39, 40-59, and 60-69. Each man walked a treadmill at a fixed grade for a period of 12 minutes, and the increase in heart rate (the difference before and after exercise) was recorded (in beats per minute). The data are shown in the table.

Chapter 15 - Nonparametric Statistics

Do the data present sufficient evidence to indicate differences in location for at least two of the four age groups? Test using the Kruskal-Wallis H test with = 0.01. What is H? Round your answer to three decimal places.

What is the critical value for the test statistic? Round your answer to four decimal places. Reject

if H >

Conclude: There is

_ of a difference in location.

Find the approximate p-value for the test above. Round your answer to two decimal places.

ANSWER:

2.632; 11.3449; Fail to reject the null hypothesis; no evidence; 0.45

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 2:31 AM 155. A movie critic wanted to determine whether or not moviegoers of different age groups evaluated a movie

differently. With this objective, he commissioned a survey that asked people their ratings of the most recently watched movies. The rating categories were: 1 = terrible, 2 = fair, 3 = good, and 4 = excellent. Each respondent was also asked to categorize his or her age as either: 1 = teenager, 2 = young adult (20-34), 3 = middle age (3550), and 4 = senior (over 50). The results are shown below.

Chapter 15 - Nonparametric Statistics

Do these data provide sufficient evidence to infer at the 5% significance level that there were differences in ratings among the different age categories? Test statistic: H=

Round your answer to three decimal places.

What is the critical value for the test statistic? Round your answer to four decimal places. Reject

if the test statistic >

Conclude: There sufficient evidence to infer at the 5% significance level that there were differences in ratings among the different age categories. What statement can be made about the p-value for this test? Round your answer to three decimal places.

ANSWER:

11.082; 7.8147; Reject the null hypothesis; is; p-value = 0.011

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 2:52 AM 156. In a Kruskal-Wallis test to determine whether differences exist among three different advertisements, the

following statistics were obtained:

Conduct the test at the 5% significance level.

Chapter 15 - Nonparametric Statistics

Test statistic: H =

Round your answer to three decimal places.

Reject

Round your answer to five decimal places.

if H >

Conclude: There advertisements.

enough evidence to conclude that differences exist among three different

What is the most accurate statement that can be made about the p-value of this test? Express your answer as interval.

ANSWER:

10.167; 5.99147; Reject the null hypothesis; is; 0.005 <= p-value <= 0.01

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 2:57 AM 157. Apply the Kruskal-Wallis test to determine if there is enough evidence at the 5% significance level to infer

that at least two populations differ.

Test statistic: H =

Round your answer to three decimal places.

Reject

Round your answer to five decimal places.

if H >

Conclude: There differ.

enough evidence at the 5% significance level to infer that at least two populations

ANSWER:

.380; 5.99147; Fail to reject the null hypothesis; is not

POINTS: QUESTION TYPE: HAS VARIABLES:

1 Subjective Short Answer False

Chapter 15 - Nonparametric Statistics STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 3:02 AM 158. The marketing manager of a pizza chain is in the process of examining some of the demographic

characteristics of her customers. In particular, she would like to investigate the belief that the ages of the customers of pizza parlors, hamburger emporiums, and fast-food chicken restaurants are different. As an experiment, the ages of eight customers of each of the restaurants are recorded and listed below. From previous analysis we know that the ages are not normally distributed.

Do these data provide enough evidence at the 10% significance level to infer that there are differences in ages among the customers of the three restaurants? Test statistic: H =

Round your answer to three decimal places.

Reject

Round your answer to five decimal places.

if H >

Conclude: There enough evidence at the 10% significance level to infer that there are differences in ages among the customers of the three restaurants. ANSWER: 4.374; 4.60517; Fail to reject the null hypothesis; is not POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 3:07 AM 159. The Friedman test is a nonparametric test that can be used to compare more than two dependent samples

when the assumptions for an analysis of variance are invalid. a. True b. False ANSWER: POINTS:

True 1

Chapter 15 - Nonparametric Statistics QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 160. The Friedman test is the nonparametric counterpart to the randomized block design of the analysis of

variance. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 161. We can use the Friedman test to determine whether a difference exists between two populations. However,

if we want to determine whether one population location is to the right of another, we must use the sign test. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 3:15 AM 162. If the Friedman test is applied to a data set that are generated from a randomized block experiment with 5

treatments and 7 blocks, then the rejection region at the 5% significance level is a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 163. The null hypothesis for the Friedman test is the k population distributions are identical. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False

Chapter 15 - Nonparametric Statistics HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 3:54 AM 164. A one-sample t-test is the parametric counterpart of the Friedman test for randomized block experimental

design. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 165. The procedure for conducting the Friedman test is very similar to that used for the Wilcoxon rank sum test. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 4:15 AM 166. If the Friedman test is applied to a data set that are generated from a randomized block experiment with 3

treatments and 5 blocks, then the rejection region at the 2.5% significance level is

> 12.8325.

a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 167. The Friedman test statistic is approximately chi-squared distributed with (k - 1) degrees of freedom,

provided that either the number of blocks b or the number of treatments k is greater than or equal to 5. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False

Chapter 15 - Nonparametric Statistics DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 168. We can use the Friedman test to determine whether two populations differ. The conclusion will be the same

as that produced from the sign test. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 169. A randomized block design analysis of variance test corresponds to: a. a Wilcoxon signed rank test for paired samples b. a Wilcoxon rank sum test c. a Wilcoxon signed rank test for one sample d. a Friedman test for randomized block design e. all of these ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 170. A three independent samples one-way analysis of variance test corresponds to: a. a Wilcoxon signed rank test for paired samples b. a Wilcoxon rank sum test c. a Wilcoxon signed rank test for one sample d. a Kruskal-Wallis test e. a Friedman test ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 171. The Friedman test is applied to problems with the following characteristics: a. the problem objective is to compare two or more populations b. the data are not normally distrubuted

Chapter 15 - Nonparametric Statistics c. the data are generated from a randomized block experiment d. all of the above e. none of the above ANSWER: d POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 3:48 AM 172. The nonparametric counterpart of the randomized block model of the analysis of variance is the: a. Kruskal-Wallis test b. Friedman test c. Wilcoxon rank sum test d. Wilcoxon signed rank test e. Wilcoxon rank sum test and Wilcoxon signed rank test ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 3:49 AM 173. The first step in the procedure for this test is to rank the k treatment observations within each block. a. the Wilcoxon signed rank test b. the sign test c. the Friedman test d. the Kruskal-Wallis test e. none of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 4:10 AM 174. In a Friedman test for comparing three populations, provided that there are five blocks, the test statistic is

calculated as = 6.594. Then, the most accurate statement that can be made about the p-value is that: a. p-value < 0.01 b. .05 < p-value < .10 c. .025 < p-value < .05

Chapter 15 - Nonparametric Statistics d. p-value > .10 e. 0.01< p-value < 0.025 ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 175. The Friedman test are always: a. one-tail b. two-tail c. used with one sample d. used when the populations are normally distributed e. used all the time ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 176. In a Friedman test for comparing four populations, provided that there as eight blocks, the test statistic is

calculated as

= 10.98. If the test is conducted at the 5% significance level, the conclusion and p-value will be:

a. reject the null hypothesis, and 0.01 < p-value < 0.025 b. reject the null hypothesis, and 0.025 < p-value < 0.05 c. do not reject the null hypothesis, and 0.025 < p-value < 0.05 d. do not reject the null hypothesis, and p-value > 0.05 e. reject the null hypothesis, p-value < 0.01 ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 4:23 AM 177. To apply the Friedman test to determine whether the locations of two or more populations are the same, the

samples must be: a. from matched pairs experiment b. from normal populations c. independent d. larger than 20

Chapter 15 - Nonparametric Statistics e. from matched pairs experiment and from normal populations ANSWER: a POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 178. If Friedman test is applied to a data set that are generated from a randomized block experiment with 4

treatments and 8 blocks, then the rejection region at the 5% significance level is: a. 1.6450 b.

7.8147

9.4877

11.0705

1.8450

ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 179. The reaction times to three stimuli were recorded for each of 8 subjects. The data, recorded in seconds, are

shown below. This problem uses Friedman's distributions of reaction times.

test to determine if there is a difference among the population

What experimental design is being used in this problem?

The null and alternate hypotheses are as follows: : The three population distributions are identical.

Chapter 15 - Nonparametric Statistics

: At least two of the three population distributions differ in location. Describe what the Test statistic

is.

Test statistic: =

Round your answer to two decimal places.

Rejection region for =0.05: Reject

Round your answer to five decimal places.

Conclusion: There is

_ evidence to conclude that the reaction times for the three stimuli are different.

Estimate the p-value for this problem? Express your answer as interval.

ANSWER:

Randomized block design; subjects are the blocks.; Fr is a function of the samples' rank sums T1, T2, and T3. To find the value of Fr, we first rank the three treatment observations within each block.; 5.25; 5.99147; Do not reject the null hypothesis; insufficient; 0.05 <= p-value <= 0.1

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 4:25 AM 180. Another school district also planned to evaluate two different workbooks and two distinct teaching

machines to assess their effectiveness in teaching the concept of multiplication. However, the administrators in this school district consulted a statistician about the design of their study. Because they were looking for a method effective on children of all abilities, the statistician suggested they check the children's past scholastic records and divide the children into groups according to their ability level. These ability groups represent relatively homogeneous experimental units within which the comparison of teaching methods may be made. She assigned one child from each ability level to each teaching method. Twenty students participated in the study. After receiving instruction, the children took a multiplication test and the number of errors they made were recorded.

Chapter 15 - Nonparametric Statistics

What experimental design did the statistician use?

The null and alternate hypotheses are as follows: : The three population distributions are identical. : At least two of the three population distributions differ in location. Describe what the test statistic

is.

Test Statistic: =

Round your answer to two decimal places.

Reject Region: Reject

if F >

Round your answer to five decimal places.

Conclude: The teaching methods

equally effective.

Estimate the observed significance level of this test.

ANSWER:

Randomized block design; ability levels are the blocks.; Fr is a function of the samples’ rank sums T1, T2, T3 and T4.; 11.58; 7.81473; Reject the null hypothesis; are not; 0.005 < p-value < 0.010

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 4:57 AM

Chapter 15 - Nonparametric Statistics 181. A toy store manager was interested in determining whether the assembly time is the same for three models

of baby strollers. The manager selected five employees at random and asked each of them to assemble each of the strollers. The assembly time, in minutes, was recorded as follows:

The manager wasn't sure whether the assumptions for the usual analysis of variance were valid, so she decided to use a nonparametric procedure. Use the appropriate method to determine whether the assembly time is the same for the three models of baby strollers. Use = 0.05. Test Statistic: =

Round your answer to two decimal places.

Reject Region: Reject

Round your answer to five decimal places.

Conclude: The distributions of assembly time for the three models of baby strollers are ANSWER: 2.80; 5.99147; Do not reject the null hypothesis; identical

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 4:58 AM 182. The general manager of a frozen TV dinner maker must decide which one of four new dinners to introduce

to the market. He decides to perform an experiment to help make a decision. Each dinner is sampled by ten people who then rate the product on a 7-point scale, where 1 = poor, and 7 = excellent. The results are shown below.

Chapter 15 - Nonparametric Statistics

Which statistical technique the general manager can use to help him make a decision?

Can the general manager infer at the 5% significance level that there are differences in the taste ratings of the four dinners? Round your answer to two decimal places. Test Statistic: Reject Region: Reject

if test statistic >

Round your answer to five decimal places.

Conclude: The general manager ratings of the four dinners.

infer at the 5% significance level that there are differences in the taste

Using the appropriate statistical table, what statement can be made about the p-value for this test?

ANSWER:

Friedman test; 14.91; 7.81473; Reject the null hypothesis; can; p-value < 0.005

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 5:03 AM 183. The restaurant critic on a newspaper claims that the hamburgers that one gets at the hamburger chain

restaurants are all equally bad and that people who claim to like one hamburger over others are victims of

Chapter 15 - Nonparametric Statistics

advertising. In fact, he claims that if there were no differences in appearance, then all hamburgers would be rated equally. To test the critic's assertion, ten teenagers are asked to taste hamburgers from three different fastfood chains. Each hamburger is dressed in the same way (mustard, relish, tomato, and pickle) with the same type of bun. The teenagers taste each hamburger and rate it on a 9-point scale with 1 = bad and 9 = excellent. The data are listed below.

Which statistical technique is appropriate if you want to compare the quality of hamburger of the three chain restaurants?

Can we infer at the 1% significance level that the critic is wrong? Round your answer to two decimal places. Test Statistic: Reject Region: Reject

if the test statistic >

Round your answer to five decimal places.

Conclude: We

infer at the 1% significance level that the critic is wrong.

Using the appropriate statistical table, what statement can be made about the p-value for this test?

ANSWER:

Friedman test; 7.80; 9.21034; Do not reject the null hypothesis; cannot; 0.01 < pvalue < 0.025

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic

Chapter 15 - Nonparametric Statistics DATE CREATED: DATE MODIFIED:

2/4/2019 9:49 AM 4/22/2019 5:07 AM

184. The following data were generated from a blocked experiment. Conduct a Friedman test at the 5%

significance level to determine if at least two population locations differ.

Test Statistic: =

Round your answer to two decimal places.

Reject Region: Reject

Round your answer to five decimal places.

Conclude: The locations of all four populations are . ANSWER: 4.20; 7.81473; Do not reject the null hypothesis; the same POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 5:09 AM 185. Apply the Friedman test to the accompany table of ordinal data to determine whether we can infer at the

10% significance level that at least two population locations differ.

Test Statistic:

Chapter 15 - Nonparametric Statistics

Round your answer to two decimal places.

Reject Region: Reject

Round your answer to five decimal places.

Conclude: We ANSWER:

infer at the 10% significance level that at least two population locations differ. 6.30; 6.25139; Reject the null hypothesis; can

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 5:13 AM 186. The Spearman rank-correlation test is a nonparametric test that uses the directions of differences observed

in a matched-pairs sample to determine whether the relative frequency distributions of two statistical populations are identical to or different from one another. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 187. The Spearman rank-correlation is a nonparametric test that 1) uses the directions of differences observed in

a matched-pairs sample to determine whether the relative frequency distributions of two statistical populations are identical to or different from one another and 2) determines whether a sample comes from a population with a specified median. a. True b. False ANSWER: False POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 188. The Spearman rank correlation coefficient is calculated by first ranking the data values, and then

Chapter 15 - Nonparametric Statistics

calculating the Pearson correlation coefficient of the ranks. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 189. The population Spearman correlation coefficient is labeled

, and the sample statistic used to estimate its

value is labeled . a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 190. To determine if a relationship exists between two variables, the hypotheses to be tested are

. a. True b. False ANSWER: True POINTS: 1 QUESTION TYPE: True / False HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 6:32 AM 191. The rank correlation coefficient is used when one is: a. correlating quantitative data b. correlating rankings of individual values for two variables c. analyzing data which are assumed to be linearly related d. not interested in drawing inferences from the study e. analyzing data which are assumed to be non-linearly related ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM

Chapter 15 - Nonparametric Statistics DATE MODIFIED: 2/4/2019 9:49 AM 192. Which of the following statements about Spearman's rank-correlation coefficient is false? a. It is the test statistic used in Spearmen's rank-correlation test, symbolized by . b. It can only take on values between 0 and + 1. c. Positive values near + 1 point to a monotonically increasing relationship between the two variables,

such that steady increases in one are associated with steady increases in the other. d. None of these. e. All of these. ANSWER: b POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 193. Spearman's rank-correlation coefficient can only take on values between: a. 0 and b.

and 0 c. 1 and +1 d. and +1 e. and ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 2/4/2019 9:49 AM 194. When the relationship between two variables is monotonically decreasing, the value of Spearman's rank-

correlation coefficient may well equal: a. 0 b. 1 c. d. e. ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 6:38 AM

Chapter 15 - Nonparametric Statistics 195. When there are no ties in either the x observations or the y observations, the expression for the Spearman

rank correlation coefficient, rs, is a. where di = (xi – yi) b. where di = (xi – yi) c. where di = (xi – yi) d. where di = (xi – yi) e. where di = (xi – yi) ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/23/2019 3:24 AM 196. In testing H0: rs = 0 vs. Ha: rs ≠ 0 at the 5% significance level, a sample of size 20 is used. The rejection

region is: a. -.377

. 377

.377 or

-.377

.450 or

-.450

d. -.450

. 450 e. none of these ANSWER: c POINTS: 1 QUESTION TYPE: Multiple Choice HAS VARIABLES: False DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 6:53 AM 197. Two psychometricians (educators who are experts in the field of psychological test design) were asked to

rank six designs for a new standardized college entrance exam.

Chapter 15 - Nonparametric Statistics

This problem uses Spearman's rank correlation coefficient to see if there is a (positive) relationship between the educators' rankings. The null and alternate hypotheses are as follows: (There is no association between the rank pairs) (The correlation between the rank pairs is positive) Describe why the test statistic is called the rank correlation coefficient.

Test Statistic: =

Round your answer to three decimal places.

Rejection region (for = 0.05): Reject

Round your answer to three decimal places.

Conclude: There educators' rankings.

sufficient evidence to indicate there is any significant positive correlation between the

What does this result mean in the context of the problem?

What is the observed significance level for this test? Express your answer as interval.

ANSWER:

The test statistic rs is called the rank correlation coefficient simply because it is the usual correlation coefficient applied to ranks.; .657; 0.829; Do not reject the null hypothesis; is not; The two educators do not agree on the design rankings. One would hope for a positive correlation indicating the designs one educator thought were better, the other educator also thought were better.; p-value > 0.05

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM

Chapter 15 - Nonparametric Statistics DATE MODIFIED:

4/22/2019 6:54 AM

198. A professor was interested in the relationship between a student's rank on an oral exam and the student's

rank on a written exam. The professor selected 8 students at random and ranked their scores for both the oral exam and the written exam. The following data was recorded:

Find and interpret the rank correlation between a student's rank on the oral exam and the student's rank on the written exam. Compute :

Round your answer to three decimal places.

There is written exam.

_ relationship between the student's rank on the oral exam and the student's rank on the

ANSWER:

.881; a strong

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 6:55 AM 199. The following paired observations were obtained on two variables x and y:

Calculate Spearman's rank correlation coefficient : Round your answer to three decimal places. Do the data present sufficient evidence to indicate a correlation between x and y? Test using = 0.05. Reject Region: Reject

if |

Round your answer to three decimal places.

Chapter 15 - Nonparametric Statistics

Conclude:

There

correlation between x and y. -.994; .886; Reject the null hypothesis; is a

ANSWER:

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/23/2019 4:15 AM 200. A school principal suspected that a teacher's attitude toward a first-grader depended on his original

judgment of the child's ability. The principal also suspected that much of that judgment was based on the firstgrader's IQ score, which was usually known to the teacher. After three weeks of teaching, a teacher was asked to rank the nine children in his class from 1 (highest) to 9 (lowest) as to his opinion of their ability.

Do the data provide sufficient evidence to indicate a positive correlation between the teacher's ranks and the ranks of the IQs? Use = .05. Test Statistic: =

Round your answer to four decimal places.

Reject Region: Reject

if |

Round your answer to two decimal places.

Conclude:

A positive correlation ANSWER:

between the teacher's ranks of the IQs. .8333; .60; Reject the null hypothesis; exists

POINTS: 1 QUESTION TYPE: Subjective Short Answer HAS VARIABLES: False STUDENT ENTRY MODE: Basic DATE CREATED: 2/4/2019 9:49 AM DATE MODIFIED: 4/22/2019 6:57 AM

Chapter 15 - Nonparametric Statistics