Test Bank For Elementary Statistics, 4th Edition by William Navidi, Barry Monk Chapter 1-15 by StudyGuide

Exam Name___________________________________

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Is the following variable at the interval or the ratio level of measurement?

The price of a loaf of bread A) Interval

B) Ratio

2) In an experiment, subjects are put into two categories according to sex, and then each

subject is randomly assigned a treatment . This is an example of... A) observational studies B) gender bias C) confounding D) randomized blocking 3) Determine which of the following describes qualitative data.

i). the volume of a shipping container, in gallons ii). the name of the material from which the container is made iii). the shape of the container A) i, ii, and iii B) i and iii only C) ii and iii only

D) i and ii only

4) A college basketball team held a promotion at one of its games in which every twentieth

person who entered the arena won a free basketball. What kind of sample do the winners represent? A) Systematic B) Voluntary response C) Stratified 5) Which one of the following data are discrete?

A) the average preseason ranking of the University of Connecticut's women's

basketball team over the past 10 years B) the height of the tallest player on Duke University's men's basketball team C) the pre-season ranking of Duke University's men's basketball team D) the average height of players on the University of Connecticut's women's basketball team 6) In a ________ experiment, subjects do not decide for themselves which treatment they

will get. A) double-blind

B) observational

C) randomized

D) prospective

7) You ask your friends who they plan to vote for in the next congressional election. Based

on their responses, you conclude that the candidate you favor cannot lose! This is most likely an example of ... A) voluntary response bias C) sampling bias

B) self-interest bias D) randomized sampling

8) A study in which the assignment to treatment groups is not made by the investigator is

called ________. A) double-blind

B) prospective

C) randomized

D) observational

9) Determine which of the following describes qualitative data.

i). the make of the car with license plate number VNS-862 ii). the license plate number VNS-862 iii). the number of vehicles whose license plate number begins with "VNS" A) i and ii only B) iii only C) neither i, nor ii, nor iii D) i only 10) Which one of the following data are discrete?

10)

A) the number of crew members on the boat B) the latitude and longitude of a boat at sea C) the speed of the boat's propeller, in revolutions per minute D) the latitude and longitude of the boat's port of departure 11) Determine which of the following describes ordinal data.

11)

i. In the horse race, Betty's Girl won, Mr. Ed placed, and Wabash showed. ii. In the horse race, I bet on Betty's Girl to win, Mr. Ed to place, and Wabash to show. A) ii only B) neither i nor ii C) both i and ii D) i only 12) Determine which of the following describes quantitative data.

i). the name of a chemical sample ii). the mass of a chemical sample iii). the color of a chemical sample A) i and ii only B) i, ii, and iii

C) i only

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D) ii only

13) A medical researcher wants to determine whether exercising can lower blood pressure.

13)

At a health fair, he measures the blood pressure of 100 individuals and interviews them about their exercise habits. He divides the individuals into two categories: those whose typical level of exercise is low, and those whose level of exercise is high. Is this a randomized experiment or an observational study? A) Randomized experiment B) Observational study 14) Is the following variable at the interval or the ratio level of measurement?

The weight in pounds of a sack of potatoes A) Interval

14)

B) Ratio

15) Is the following variable at the interval or the ratio level of measurement?

The year of your birth A) Interval

B) Ratio

15)

16) A middle school student passes out leaflets to the adults at a school function. The leaflets

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ask the recipient to indicate whether they believe in anthropogenic global warming. The bottom of the leaflet indicates that the completed leaflet should be returned to the student. Identify the kind of sample that is being used. A) stratified sample B) sample of convenience C) systematic sample D) cluster sample 17) Determine which of the following describes ordinal data.

i. My best friends are Georgia, Amithaba, and Raphael. ii. My favorite numbers are 2, 7 and 13. A) neither i nor ii B) ii only C) both i and ii

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D) i only

18) Determine which of the following describes nominal data.

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i. Michaelangelo's sells small, medium, large, and jumbo pizzas. ii. Michaelangelo's most-requested toppings are pepperoni, black olives, and mushrooms. A) both i and ii B) i only C) ii only D) neither i nor ii 19) People are reluctant to admit to behavior that may reflect negatively on them. This can

lead to ... A) social acceptability bias C) sampling bias

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B) hurt feelings D) voluntary response bias

20) A pollster randomly samples 145 Democrats, 154 Republicans and 19 Independents (all

20)

registered voters) in Metro City and asks each poll participant which mayoral candidate he or she prefers. Identify the kind of sample that the pollster is using. A) sample of convenience B) voluntary response sample C) stratified sample D) cluster sample 21) A public health researcher is designing a study of the effect of diet on heart disease. The

21)

researcher knows that the diets of men and women tend to differ and that men are more susceptible to heart disease. To be sure that both men and women are well represented, the study comprises a simple random sample of 100 men and another simple random sample of 100 women. What kind of sample do these 200 people represent? A) Stratified B) Voluntary response C) Cluster D) Systematic 22) Choose the answer below that best completes the following statement.

A _____________ is a number that describes a sample. A) population B) statistic C) measurement

22)

D) parameter

23) Determine which of the following describes quantitative data.

i). the length of an object in feet ii). the speed of an object in meters per second iii). the number of objects that are blue A) i only B) iii only C) i and ii only

23)

D) i, ii, and iii

24) A radio talk show host invites listeners to send an email to express their opinions on an

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upcoming election. More than 10,000 emails are received. What kind of sample is this? A) Stratified B) Voluntary response C) Systematic D) Cluster 25) Which of the following is the best description of a double-blind experiment?

25)

A) an experiment in which neither the investigators nor the subjects know how the

treatments have been assigned B) an experiment in which both the investigators and the subjects are hidden from the others' views C) an experiment in which the subjects are blindfolded so they cannot see which treatment is applied to them D) an experiment in which neither the investigators nor the subjects know the others' names 26) A pollster asks a group of six voters about their political affiliation (Republican,

26)

Democrat, or Independent), their age, and whether they voted in the last election. The results are shown in the following table.

Voter 1 2 3 4 5 6

Political Affilation Republican Democrat Democrat Independent Republican Independent

Voted in Last Election? Yes Yes No Yes No Yes

Age 34 56 21 28 61 46

What are the data for individual #3? A) Political affiliation, age, voted in last election B) Democrat, 21 C) Political affiliation D) Democrat, 21, no 27) When rolling two six-sided dice, your total roll ranges from 2 (double ones) to 12

(double sixes).Characterize the nature of the roll total. A) qualitative and discrete B) qualitative and continuous C) quantitative and continuous D) quantitative and discrete 4

27)

28) To study the effect of air pollution on respiratory health, a group of people in a city with

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high levels of air pollution and another group in a rural area with low levels of pollution are examined to determine their lung capacity. Is this a randomized experiment or an observational study? A) randomized experiment B) observational study 29) An electronics manufacturer test every 50th cell phone to verify that it is functioning

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properly. Identify the kind of sample that is being used. A) cluster sample B) stratified sample C) systematic sample D) simple random sample 30) Is the following variable at the interval or the ratio level of measurement?

The year you started school A) Interval

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B) Ratio

31) In a randomized experiment, if there are large differences in outcomes among the

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treatment groups, we can conclude that the differences are due to _____________________. A) the treatments B) random luck C) deliberate data manipulation D) experimental error 32) A medical researcher wants to determine whether exercising can lower blood pressure.

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She recruits 100 people with high blood pressure to participate in the study. She assigns a random sample of 50 of them to pursue an exercise program that includes daily swimming and jogging. She assigns the other 50 to refrain from vigorous activity. She measures the blood pressure of each of the 100 individuals both before and after the study. Is this a randomized experiment or an observational study? A) Randomized experiment B) Observational study 33) In a study conducted at the University of Colorado, J. Ruttenber and colleagues studied

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people who had worked at the Rocky Flats nuclear weapons production facility near Denver, Colorado. They studied a group of workers who had contracted lung cancer and another group who had not contracted lung cancer. They looked back at plant records to determine the amount of radiation exposure for each worker. The purpose of the study was to determine whether the people with lung cancer had been exposed to higher levels of radiation than those who had not gotten lung cancer. Was this a cohort study or a case-control study? A) Cohort study B) Case-control study 34) Is the following variable at the interval or the ratio level of measurement?

Your age in years A) Interval

B) Ratio

34)

35) A ________ is a variable related to both the treatment and the outcome. A) dependent

B) perplexer

C) cohort

35) D) confounder

36) Which one of the following data are continuous?

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A) all of these represent continuous data B) the number of musicians performing in the MP3 file C) the number of times the file has been downloaded D) the time remaining for an MP3 music download 37) In a recent study, Z. Zhao and colleagues measured the levels of formaldehyde in the air

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in 34 classrooms in the schools in the city of Taiyuan, China. On the same day, they gave questionnaires to 1993 students aged 11–15 in those schools, asking them whether they had experienced respiratory problems (such as asthma attacks, wheezing, or shortness of breath). They found that the students in the classrooms with higher levels of formaldehyde reported more respiratory problems. Was the study prospective, cross-sectional, or retrospective? A) Cross-sectional B) Prospective C) Retrospective 38) Which one of the following data are continuous?

38)

A) the number of representatives of each species in the park B) the rankings of the trees, from most numerous to least numerous C) the average height of a sample of trees D) the number of species of trees in a park 39) Which of the following is the best description of a randomized experiment?

39)

A) an experiment in which the investigators are chosen at random B) an experiment in which the outcomes are random C) an experiment in which the treatments are assigned randomly to experimental units D) an experiment in which the experimental units are selected at random 40) In a study conducted at the University of Colorado, J. Ruttenber and colleagues studied

people who had worked at the Rocky Flats nuclear weapons production facility near Denver, Colorado. They studied a group of workers who had contracted lung cancer and another group who had not contracted lung cancer. They looked back at plant records to determine the amount of radiation exposure for each worker. The purpose of the study was to determine whether the people with lung cancer had been exposed to higher levels of radiation than those who had not gotten lung cancer. Was the study prospective, cross-sectional, or retrospective? A) Retrospective B) Prospective C) Cross-sectional

40)

41) Every 10 years, the U.S. Census Bureau attempts to count every person living in the

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United States. To check the accuracy of their count in a certain city, they draw a sample of census districts (roughly equivalent to a city block) and recount everyone in the sampled districts. What kind of sample is formed by the people who are recounted? A) Voluntary response B) Stratified C) Systematic D) Cluster 42) A recent study compared the heart rates of 19 infants born to nonsmoking mothers with

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those of 17 infants born to mothers who smoked an average of 15 cigarettes a day while pregnant and after giving birth. The heart rates of the infants at one year of age were 20% slower on the average for the smoking mothers. Was this a cohort study or a case-control study? A) Cohort study B) Case-control study 43) A pollster asks a group of six voters about their political affiliation (Republican,

43)

Democrat, or Independent), their age, and whether they voted in the last election. The results are shown in the following table.

Voter 1 2 3 4 5 6

Political Affilation Republican Democrat Democrat Independent Republican Independent

Voted in Last Election? Yes Yes No Yes No Yes

Age 34 56 21 28 61 46

Identify the variables. A) voted in last election B) Political affiliation C) Political affiliation, age, voted in last election D) age 44) A pollster wants to estimate the proportion of voters in a certain town who are

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Democrats. He goes to a large shopping mall and approaches people to ask whether they are Democrats. Is this a simple random sample? A) yes B) no 45) Is the following variable at the interval or the ratio level of measurement?

The sales price of a car A) Interval

B) Ratio

45)

46) In a study conducted at the University of Southern California, J. Peters and colleagues

46)

studied elementary school students in 12 California communities. Each year for 10 years, they measured the respiratory function of the children and the levels of air pollution in the communities. Was this a cohort study or a case-control study? A) Cohort study B) Case-control study 47) By visiting homes door-to-door, a municipality surveys all the households in 149

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randomly-selected neighborhoods to see how residents feel about a proposed property tax increase. Identify the type of sample that is being used. A) systematic sample B) cluster sample C) voluntary response sample D) stratified sample 48) Choose the answer below that best completes the following statement.

A ________ is a number that describes a population. A) summary B) statistic C) parameter

48)

D) sample

49) Determine which of the following describes nominal data.

49)

i. My favorite days of the week are Friday, Saturday, and Tuesday. ii. My favorite day of the week is Friday, my second-favorite is Saturday, and third-favorite is Tuesday. A) both i and ii B) neither i nor ii C) ii only D) i only 50) A recent study compared the heart rates of 19 infants born to nonsmoking mothers with

50)

those of 17 infants born to mothers who smoked an average of 15 cigarettes a day while pregnant and after giving birth. The heart rates of the infants at one year of age were 20% slower on the average for the smoking mothers. Was the study prospective, cross-sectional, or retrospective? A) Retrospective B) Cross-sectional C) Prospective 51) In a study conducted at the University of Southern California, J. Peters and colleagues

51)

studied elementary school students in 12 California communities. Each year for 10 years, they measured the respiratory function of the children and the levels of air pollution in the communities. Was the study prospective, cross-sectional, or retrospective? A) Retrospective B) Cross-sectional C) Prospective 52) A television newscaster invites viewers to tweet their opinions on a proposed bill on

immigration policy. More than 50,000 people express their opinions in this way. A) Systematic B) Voluntary response C) Stratified D) Cluster

52)

53) A telephone company wants to estimate the proportion of customers who are satisfied

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with their service. They use a computer to generate a list of random phone numbers and call those people to ask them whether they are satisfied. Is this a simple random sample? A) yes B) no 54) Is the following variable at the interval or the ratio level of measurement?

The time that your first class starts A) Interval

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B) Ratio

55) The names of all 126 students in a professor's class are written on identical slips of

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paper, and the slips are placed into a large glass jar. Then, the professor selects 14 random slips from the jar. Identify the kind of sample that is being used. A) simple random sample B) sample of convenience C) cluster sample D) systematic sample 56) Is the following variable at the interval or the ratio level of measurement?

56)

The score on an SAT exam (range is 200 to 800 points) A) Interval B) Ratio 57) In a recent study, Z. Zhao and colleagues measured the levels of formaldehyde in the air

57)

in 34 classrooms in the schools in the city of Taiyuan, China. On the same day, they gave questionnaires to 1993 students aged 11–15 in those schools, asking them whether they had experienced respiratory problems (such as asthma attacks, wheezing, or shortness of breath). They found that the students in the classrooms with higher levels of formaldehyde reported more respiratory problems. Was this a cohort study or a case-control study? A) Cohort study B) Case-control study 58) The question...

58)

"Do you favor a higher standard of living, even though it produces unclean air and water?" ... is an example of ... A) framing B) leading question bias C) sampling bias D) random sampling 59) Which of the following sample types should you always regard as unreliable? A) voluntary response samples

B) stratified samples

C) cluster samples

D) simple random samples

60) An app produces a message requesting customers to click on a link to rate the app. A) Voluntary response

B) Cluster

C) Systematic

59)

60)

61) In a small town, 84% of the residents, aged 16 or more years old, own a car. Is this an

example of statistic or a parameter? A) Statistic

61)

B) Parameter

62) A radio talk show invites people to call in and state whether or not they think that sexual

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harassment in the work place is a common problem. A) Voluntary response B) Self-interest C) Sampling D) Social acceptability 63) In a recent poll, 64% of the respondents supported stricter gun laws. Is this an example

of statistic or a parameter? A) Statistic

B) Parameter

64) When experimental units are people, they are sometimes called ________________. A) personnel

63)

B) human units

C) subjects

64)

D) topics

65) A small brew pub sent out questionnaires to a simple random sample of 250 customers

65)

asking whether they would like the brewery to include an imperial stout in their regular offerings. Of the 250 questionnaires, 12 were returned and 10 of those were in favor of including the stout. Specify the type of bias involved. A) Sampling B) Nonresponse C) Voluntary response D) Self-interest 66) A(n) _______________ makes it difficult to determine whether an experimental

outcome is due to the applied treatment. A) confounder C) uncooperative subject

B) perplexer D) error

67) Of the televisions offered at an electronics store, 42% cost less than $500.00. Is this an

example of statistic or a parameter? A) Statistic

67)

B) Parameter

68) The characteristics of individuals about which we collect information are called

________. A) clusters

66)

B) variables

C) samples

69) A ________ is a type of sample that is analogous to a lottery. A) sample of convenience

B) population

C) simple random sample

D) cluster

68)

D) data 69)

70) A pollster asks a group of six voters about their political affiliation (Republican,

70)

Democrat, or Independent), their age, and whether they voted in the last election. The results are shown in the following table.

Voter 1 2 3 4 5 6

Political Affilation Republican Democrat Democrat Independent Republican Independent

Age 34 56 21 28 61 46

Voted in Last Election? Yes Yes No Yes No Yes

How many individuals are there? A) 74 B) 6

C) 21

D) 246

71) In a survey of 1000 teenagers, 23% of them said they use tobacco products. Is this an

example of statistic or a parameter? A) Statistic

B) Parameter

72) The values of variables are called ________. A) data

71)

72)

B) variables

C) clusters

D) samples

73) An experiment that tends to overestimate or underestimate the true value is said to be

______________. A) biased C) un-randomized

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B) randomized D) flagrant

74) A sign in a grocery store claims that 92% of their customers believe them to have the

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freshest produce in the city. Specify the type of bias involved. A) Voluntary response B) Social acceptability C) Self-interest D) Leading question 75) In an experiment, the ______________ is what is measured on each experimental unit. A) subject

B) treatment

C) outcome

75)

D) category

76) A ________ is a subset of a population.

76)

A) sample

B) sample of convenience

C) cluster

D) simple random sample

77) The entire collection of individuals about which information is sought is called a

________. A) population C) cluster

B) simple random sample D) sample 11

77)

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 78) Determine whether the statement is true or false.

78)

In a cross-sectional study, measurements are made at only one point in time. 79) Determine whether the statement is true or false.

79)

A sample of convenience is never acceptable. 80) Determine whether the statement is true or false.

80)

In a case-control study, the outcome has occurred before the subjects are sampled. 81) Determine whether the statement is true or false.

Observational studies are generally more reliable than randomized experiments.

81)

Answer Key Testname: C1

1) B 2) D 3) C 4) A 5) C 6) C 7) C 8) D 9) A 10) A 11) C 12) D 13) B 14) B 15) A 16) B 17) A 18) C 19) A 20) C 21) A 22) B 23) D 24) B 25) A 26) D 27) D 28) B 29) C 30) A 31) A 32) A 33) B 34) B 35) D 36) D 37) A 38) C 39) C 40) A 41) D 42) A 43) C 44) B 45) B 46) A 47) B 48) C 49) D 50) C 13

Answer Key Testname: C1

51) A 52) B 53) A 54) A 55) A 56) A 57) A 58) B 59) A 60) A 61) B 62) A 63) A 64) C 65) B 66) A 67) B 68) B 69) C 70) B 71) A 72) A 73) A 74) C 75) C 76) A 77) A 78) TRUE 79) FALSE 80) TRUE 81) FALSE

Exam Name___________________________________

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Classify the following histogram as skewed to the left, skewed to the right,

apporximately bell-shaped, or approximately uniformly distributed.

A) Skewed left

B) Approximately uniform

C) Bell-shaped

D) Skewed right

2) The following time-series plot presents the percentage of high school seniors who

smoked cigarettes every two years form 1994 through 2018.

In what year was the percentage the lowest? A) 2018 B) 2006

C) 2010

D) 1994

3) The Nielsen Company estimated the numbers of people in various gender and age

categories who used a video game console. The results are presented in the following frequency distribution. Frequency (in millions) 13.0 10.1 9.6 6.2 16.1 11.6 10.4 9.3 3.5 3.9

Gender and Age Group Males 2-11 Females 2-11 Males 12-17 Females 12-17 Males 18-34 Females 18-34 Males 35-49 Females 35-49 Males 50+ Females 50+

i. More than half of video gamer are male. ii. More than 40% of video gamers are female. iii. The proportion of video games that are 35 and over is 0.289. Which statement(s) are true? A) i C) ii

B) ii and iii D) All statements are true.

4) A sample of 200 high school students were asked how many hours per week they spend

watching television. The following frequency distribution presents the results.

Construct a relative frequency polygon for the frequency distribution.

5) Classify the following histogram as skewed to the left, skewed to the right,

apporximately bell-shaped, or approximately uniformly distributed.

A) Skewed left

B) Approximately uniform

C) Skewed right

D) Bell-shaped

6) The following time-series plot and bar graph both present the sales of digital music for

the years 2013-2018. Which of the graphs presents the more accurate picture?

A) bar graph

B) time-series plot

7) Classify the following histogram as skewed to the left, skewed to the right,

apporximately bell-shaped, or approximately uniformly distributed.

A) Bell-shaped

B) Skewed right

C) Skewed left

D) Approximately uniform

8) The following pie chart presents the percentages of fish caught in each of four ratings

categories. Match this pie chart with its corresponding bar graph.

9) The following time-series plot presents the percentage of high school seniors who

smoked cigarettes every two years form 1994 through 2018.

During what period of time was the percentage increasing? A) 1994-1998 B) 1994-2004 C) 2006-2012

D) 2002-2006

10) Classify the histogram as skewed to the left, skewed to the right, bell-shaped, or

approximately uniform.

A) Bell-shaped

B) Approximately uniform

C) Skewed left

D) Skewed right

10)

11) The gross domestic product (GDP) of the United States is the total value of all goods and

11)

services produced in the country. In 2000, the GDP was $10.0 trillion. In 2019, the GDP was $21.0 trillion, slightly more than twice as much. Which of the following graphs compares these totals more accurately? (Source: St. Louis Federal Reserve) A)

12) Classify the following histogram as unimodal or bimodal.

A) Unimodal

B) Bimodal

12)

13) List the data in the following stem-and-leaf plot. The leaf represents the tenths digit.

13)

14 4 6 8 9 15 1 2 2 4 5 7 7 8 16 0 1 1 1 2 3 7 7 9 17 18 2 3 8 A) 14.4, 14.6, 14.8, 14.9, 15.1, 15.2, 15.4, 15.5, 15.7, 15.8, 16.0, 16.1, 16.2, 16.3, 16.7, 16.9, 18.2, 18.3, 18.8 B) 144, 146, 148, 149, 151, 152, 154, 155, 157, 158, 160, 161, 162, 163, 167, 169, 182, 183, 188 C) 144, 146, 148, 149, 151, 152, 152, 154, 155, 157, 157, 158, 160, 161, 161, 161, 162, 163, 167, 167, 169, 182, 183, 188 D) 14.4, 14.6, 14.8, 14.9, 15.1, 15.2, 15.2, 15.4, 15.5, 15.7, 15.7, 15.8, 16.0, 16.1, 16.1, 16.1, 16.2, 16.3, 16.7, 16.7, 16.9, 18.2, 18.3, 18.8 14) A sample of 200 high school students were asked how many hours per week they spend

watching television. The following frequency distribution presents the results.

Construct a relative frequency ogive for the frequency distribution. A)

14)

15) The following time-series plot presents the average price of houses sold in the United

15)

States during the first quarter of each of the years 2004-2019.

Estimate the average house price in 2005. A) $320,000 B) $270,000

C) $310,000

D) $300,000

16) A sample of 200 high school students were asked how many hours per week they spend

watching television. The following frequency distribution presents the results.

Construct a frequency ogive for the frequency distribution. A)

16)

17) The number of cable television subscribers has been declining in recent years. Following

are two bar graphs that illustrate the decline. (Source: Business Insider)

Choose one of the following options, and explain shy it is correct: (i) Graph A presents and accurate picture, and graph B exaggerates the decline. (ii) Graph B presents an accurate picture, and graph A understates the decline. A) (ii) B) (i)

17)

18) The following time-series plot presents the percentage of high school seniors who

18)

smoked cigarettes every two years form 1994 through 2018.

What was the first year that the percentage was below 15%? A) 2018 B) 2008 C) 2006

D) 2010

19) The following pie chart presents the percentages of fish caught in each of four ratings

categories. Match this pie chart with its corresponding Pareto chart.

19)

20) The following bar graph presents the average amount a U.S. family spent, in dollars, on

20)

various food categories in a recent year.

On which food category was the most money spent? A) Fruit and vegetables B) Cereals and bakery products C) Dairy products D) Meat, poultry, fish, and eggs 21) Classify the histogram as skewed to the left, skewed to the right, bell-shaped, or

approximately uniform.

A) Bell-shaped

B) Approximately uniform

C) Skewed left

D) Skewed right

21)

22) Classify the histogram as skewed to the left, skewed to the right, bell-shaped, or

approximately uniform.

A) Bell-shaped

B) Skewed left

C) Approximately uniform

D) Skewed right

22)

23) The Dow Jones Industrial Average reached its lowest point in recent history on October

9, 2008, when it closed at $8,579. Ten years later, on October 9, 2018, the average had risen to $26,486.78. Which of the following graphs accurately represents the magnitude of the increase? A)

23)

24) The following time-series plot presents the average price of houses sold in the United

24)

States during the first quarter of each of the years 2004-2019.

Was the average price in 2006 greater than, less than, or about the same as the average price in 2013? A) Less than B) Greater than C) About the same 25) Classify the following histogram as unimodal or bimodal.

A) Bimodal

B) Unimodal

25)

26) Following is a frequency distribution that presents the number of live births to women

26)

aged 15-44 in the state of Wyoming in a recent year. Distribution of Births by Age of Mother Age Frequency 15-19 795 20-24 2410 25-29 2190 30-34 1208 35-39 499 40-44 109 What is the class width? A) 4 B) 25

C) 5

D) 24

27) Following is a frequency distribution that presents the number of live births to women

aged 15-44 in the state of Wyoming in a recent year. Distribution of Births by Age of Mother Age Frequency 15-19 795 20-24 2410 25-29 2190 30-34 1208 35-39 499 40-44 109 List the lower class limits. A) 20, 25, 30, 26, 40, 45 C) 19, 24, 29, 34, 39, 44

B) 16, 21, 26, 31, 36, 41 D) 15, 20, 25, 30, 35, 40

27)

28) Classify the histogram as skewed to the left, skewed to the right, bell-shaped, or

28)

approximately uniform.

A) Skewed right

B) Approximately uniform

C) Skewed left

D) Bell-shaped

29) In a stem-and-leaf plot, the rightmost digit of each data value is the A) plot

B) leaf

C) stem

29)

D) count

30) Classify the following histogram as skewed to the left, skewed to the right,

30)

apporximately bell-shaped, or approximately uniformly distributed.

A) Skewed left

B) Bell-shaped

C) Skewed right

D) Approximately uniform

31) In a back-to-back stem-and-leaf plot, each of the two data sets plotted must have the

same A) stems

. B) leaves

C) median

D) data values

31)

32) Following is a pie chart that presents the percentages of video games sold in each of four

32)

rating categories.

In which rating category are the most games sold? A) Everyone 10+ B) Everyone C) Teen

D) Mature

33) The following time-series plot presents the percentage of high school seniors who

smoked cigarettes every two years form 1994 through 2018.

During what period of time was the percentage decreasing? A) 1998-2006 B) 2006-2018 C) 1998-2018

D) 1994-2002

33)

34) The following time-series plot presents the average price of houses sold in the United

34)

States during the first quarter of each of the years 2004-2019.

In 2008, an economic downturn known as the Great Recession occurred. What was the effect on the average house price? A) It stayed the same. B) It decreased. C) It increased. 35) Of the 100 members of the United States Senate recently, 75 were men and 25 were

women. The following three-dimensional bar graph attempts to present this information.

Is this graph misleading or not misleading? A) not misleading

B) misleading

35)

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. 36) Chocolate or vanilla: The following bar graph shows the number of chocolate

36)

and vanilla ice cream cones sold during the annual county fair for the years 2013 - 2017. Does the graph present an accurate picture of the difference between chocolate and vanilla cones sold? Or is it misleading? Explain.

37) Toy sales: The following graph presents the percent market share for the US Toy

37)

Retail Sales between brick and mortar toy sales and online sales for the years 2011-2015. Does the graph present an accurate picture of the differences in revenue from these two sources? Or is it misleading? Explain.

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 38) Thirty households were surveyed for the number of televisions in each home. Following

are the results.

Construct a relative frequency histogram.

38)

39) Construct a dotplot for the following data.

39)

40) The following frequency distribution presents the frequency of passenger vehicles that

pass through a certain intersection from 8:00 AM to 9:00 AM on a particular day. Vehicle Type Motorcycle Sedan SUV Truck

Frequency 10 73 84 32

Construct a relative frequency distribution for the data.

40)

Vehicle Type Motorcycle Sedan SUV Truck

Relative Frequency 0.1 0.73 0.84 0.32

Vehicle Type Motorcycle Sedan SUV Truck

Relative Frequency 0.05% 0.367% 0.422% 0.161%

Vehicle Type Motorcycle Sedan SUV Truck

Relative Frequency 0.119 0.869 1 0.381

Vehicle Type Motorcycle Sedan SUV Truck

Relative Frequency 0.05 0.367 0.422 0.161

41) The following table presents the purchase totals (in dollars) of a random sample of

gasoline purchases at a convenience store. Construct a relative frequency distribution using a class width of 10, and using 0 as the lower class limit for the first class.

41)

42) A sample of 200 high school students were asked how many hours per week they spend

watching television. The following frequency distribution presents the results.

Construct a frequency polygon for the frequency distribution. A)

42)

43) Following is a pie chart that presents the percentages spent by a certain household on its

43)

five largest annual expenditures. What percentage of the money spent was spent on food, housing, and utilities?

A) 47%

B) 52.5%

C) 65.4%

44) Construct a stem-and-leaf plot for the following data.

D) 60.4% 44)

45) The following time-series plot presents the population growth (in percent) of a suburb of

Atlanta, Georgia for each of the years 1990 through 2009. Estimate the rate of growth in 2001.

A) 5.9%

B) 5.6%

C) 3.8%

D) 4.8%

45)

46) The following frequency distribution presents the frequency of passenger vehicles that

46)

pass through a certain intersection from 8:00 AM to 9:00 AM on a particular day. Vehicle Type Motorcycle Sedan SUV Truck

Frequency 12 59 38 64

Construct a pie chart for the data. A)

47) The following frequency distribution presents the frequency of passenger vehicles that

pass through a certain intersection from 8:00 AM to 9:00 AM on a particular day. Vehicle Type Motorcycle Sedan SUV Truck

Frequency 5 56 54 62

Construct a relative frequency bar graph for the data.

47)

48) One hundred students are shown an eight-digit number on a piece of cardboard for three

48)

seconds and are asked to then recite the number from memory. The process is repeated until the student accurately recites the entire number from memory. The following histogram presents the number of trials it took each student to memorize the number.

How many students memorized the number in three trials or less? A) 16 B) 86 C) 14

D) 4

49) The following table presents the purchase totals (in dollars) of a random sample of

gasoline purchases at a convenience store. Construct a frequency histogram using a class width of 10, and using 0 as the lower class limit for the first class.

49)

50) The following frequency distribution presents the frequency of passenger vehicles that

pass through a certain intersection from 8:00 AM to 9:00 AM on a particular day. Vehicle Type Motorcycle Sedan SUV Truck

Frequency 10 80 75 40

Construct a frequency bar graph for the data. 36

50)

51) The following frequency distribution presents the weights in pounds (lb) of a sample of

visitors to a health clinic.

Construct a relative frequency histogram. A)

51)

52) Helium prices: The cost of grade A Helium gas in 2003 was around $60/Mcf. Five years

52)

later it reached around $115/Mcf. Which of the following graphs accurately represents the magnitude of the increase? A)

2003 53) Construct a dotplot for the following data.

2008 53)

54) The following bar graph presents the average amount a certain family spent, in dollars,

54)

on various food categories in a recent year. On which food category was the most money spent?

A) Meat poultry, fish, eggs

B) Cereals and baked goods

C) Fruits and vegetables

D) Dairy products

55) The following table presents the rate of population growth of a suburb of Atlanta,

Georgia for each of the years 1990 through 2009. Construct a time-series plot of the growth rate.

55)

56) The following frequency distribution presents the weights in pounds (lb) of a sample of

56)

visitors to a health clinic. Weight (lb) 100-103 104-107 108-111 112-115 116-119 120-123 124-127 128-131

Frequency 2 5 4 3 6 5 3 2

What is the class width? A) 5 B) 3

C) 4

D) 32

57) The following frequency distribution presents the frequency of passenger vehicles that

57)

pass through a certain intersection from 8:00 AM to 9:00 AM on a particular day. Vehicle Type Motorcycle Sedan SUV Truck

Frequency 12 86 66 30

What is the relative frequency of the Truck category? A) 0.155 B) 30% C) 30

D) 0.349

58) The following table presents the purchase totals (in dollars) of a random sample of

gasoline purchases at a convenience store. Construct a relative frequency histogram using a class width of 10, and using 0 as the lower class limit for the first class.

58)

59) The following time-series plot presents the population growth (in percent) of a suburb of

59)

Atlanta, Georgia for each of the years 1990 through 2009. Estimate the amount by which the rate of growth changed from 2007 to 2009.

A) about -2.7 percentage points

B) about -1.9 percentage points

C) about -2.2 percentage points

D) about -2.6 percentage points

60) The following frequency distribution presents the frequency of passenger vehicles that

pass through a certain intersection from 8:00 AM to 9:00 AM on a particular day. Vehicle Type Motorcycle Sedan SUV Truck

Frequency 6 44 25 75

Construct a relative frequency Pareto chart for the data. A)

60)

61) Following are the numbers of Dean's List students in a random sample of 20 university

courses. Construct a dotplot for these data.

61)

62) The following frequency distribution presents the weights in pounds (lb) of a sample of

visitors to a health clinic.

Construct a frequency histogram.

62)

63) Classify the histogram as unimodal or bimodal.

A) bimodal

63)

B) unimodal

64) Thirty households were surveyed for the number of televisions in each home. Following

are the results.

Construct a frequency histogram. A)

64)

65) Construct a stem-and-leaf plot for the following data, in which the leaf represents the

65)

tenths place.

66) Classify the histogram as skewed to the left, skewed to the right, or approximately

symmetric.

A) skewed to the right B) approximately symmetric C) skewed to the left

66)

67) Gravity on Mars: The gravity on Earth is around

2 's stronger than the gravity on Mars. 3

67)

Which of the following graphics compare the gravity differences more accurately, and why? A)

68) The following table presents the purchase totals (in dollars) of a random sample of

gasoline purchases at a convenience store. Construct a frequency distribution using a class width of 10, and using 0 as the lower class limit for the first class.

68)

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 69) Stem-and-leaf plots and dotplots provide a simple way to display data for small data sets.

69)

70) The following frequency distribution presents the number of copies sold at retail in the

70)

United States in 2018 for each of the ten best-selling video games.

Game Spider-Man (PS4) God of War (PS4) FIFA 19 (PS4) Monster Hunter: World (PS4) Far Cry 5 (PS4) Mario Kart 8 Deluxe (Switch) Super Mario Odyssey (Switch) Call of Duty: Black Ops III (PS4) Legend of Zelda: Breath of the Wild (Switch) Splatoon

Sales (millions) 52 50 49 47 36 33 26 25 22 21

True or false: More than 10% of the games sold were Spider-Man 71) In a dotplot, the number of dots in a vertical column represents the number of times a

certain value appears in a data set.

71)

72) The following frequency distribution presents the number of phones (in millions)

72)

shipped in each quarter of each year from 2015 through 2018.

Quarter Jan.–Mar. 2015 Apr.–Jun. 2015 Jul.–Sep. 2015 Oct.–Dec. 2015 Jan.–Mar. 2016 Apr.–Jun. 2016 Jul.–Sep. 2016 Oct.–Dec. 2016 Jan.–Mar. 2017 Apr.–Jun. 2017 Jul.–Sep. 2017 Oct.–Dec. 2017 Jan.–Mar. 2018 Apr.–Jun. 2018 Jul.–Sep. 2018 Oct.–Dec. 2018

Number Sold (in millions) 354.0 334.5 359.3 387.0 369.2 365.8 356.6 432.8 380.2 379.8 380.7 444.0 375.4 435.6 429.2 458.2

True or false: In each year, the quarter with the largest sales was October to December 73) The following bar graph presents the average amount a U.S. family spent, in dollars, on

various food categories in a recent year.

True or false: Families spent more on animal products (meat, poultry, fish, eggs, and dairy products) than on plant products (cereals, bakery products, fruits, and vegetables). 54

73)

74) Following is a pie chart that presents the percentages of video games sold in each of four

74)

rating categories.

True or false: More than twice as many T-rated games are sold as M-rated games. 75) The population of country A is twice as large as the population of country B. True or

75)

false: If images are used to represent the populations, both the height and width of the image for country A should be twice as large as the height and width of the image for country B. 76) The following time-series plot presents the percentage of high school seniors who

smoked cigarettes every two years form 1994 through 2018.

True or false: Since 1994, the percentage has never been lower than 5%.

76)

77) In a stem-and-leaf plot, each stem must be a single digit.

77)

78) The following frequency distribution presents the number of phones (in millions)

78)

shipped in each quarter of each year from 2015 through 2018.

Number Sold (in millions) 337.9 346.9 341.2 384.6 362.1 377.9 356.9 419.9 341.5 340.8 353.3 443.4 428.8 439.6 397.9 448.2

True or false: Phone shipments increased each year from 2015 through 2018.

79) Following is a pie chart that presents the percentages of video games sold in each of four

79)

rating categories.

True or false: Fewer than one in five games sold is an M-rated game. 80) The following time-series plot presents the average price of houses sold in the United

States during the first quarter of each of the years 2004-2019.

True or false: The average price in 2019 exceeded the average price in 2004 by more than $100,000.

80)

81) The following bar graph presents the average amount a U.S. family spent, in dollars, on

various food categories in a recent year.

True or false: On the average, families spent more on cereals and bakery products than on fruits and vegetables.

81)

Answer Key Testname: C2

1) B 2) A 3) D 4) B 5) A 6) A 7) B 8) A 9) A 10) D 11) A 12) B 13) D 14) A 15) D 16) B 17) B 18) C 19) B 20) D 21) C 22) C 23) A 24) C 25) B 26) C 27) D 28) D 29) B 30) B 31) A 32) B 33) C 34) B 35) B 36) Misleading 37) Accurate 38) C 39) A 40) D 41) B 42) A 43) C 44) B 45) D 46) B 47) B 48) C 49) D 59

Answer Key Testname: C2

50) D 51) C 52) A 53) C 54) A 55) A 56) C 57) A 58) B 59) C 60) D 61) B 62) D 63) A 64) D 65) D 66) A 67) A 68) C 69) TRUE 70) TRUE 71) TRUE 72) TRUE 73) TRUE 74) FALSE 75) FALSE 76) FALSE 77) FALSE 78) FALSE 79) TRUE 80) TRUE 81) FALSE

Exam Name___________________________________

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Rachel worked at three part-time jobs last week. At one job, she worked 20 hours at a

salary of $14 per hour, at another she worked 9 hours at $13 per hour, and at the third she worked 13 hours at $10 per hour. What was her mean hourly wage? A) $12.94 B) $13.50 C) $12.55 D) $13.33 2) In a recent year, the 65th percentile of daily mean temperatures in the city of Macon,

Georgia was 75 degrees. For approximately what percentage of days that year was the mean temperature greater than 75 degrees? A) 35% B) 65% C) 34% D) 64% 3) Following are final exam scores, arranged in increasing order, for 28 students in an

introductory statistics course. 58 76

59 77

62 78

64 78

67 78

68 82

69 82

71 84

73 86

74 87

75 88

Fred got a score of 75 on the exam. On what percentile is his score? A) 41st B) 45th C) 36th

76 91

76 97

D) 38th

4) Use the given frequency distribution to approximate the mean.

Class 0-49 50-99 100-149 150-199 200-249 250-299 A) 145.3

Frequency 16 25 15 36 26 7 B) 145.8

C) 20.8

D) 97.0

5) The following frequency distribution presents the number of U.S. adults (in thousands)

ages 25–74 who have earned a Bachelor’s degree in a recent year. Class 25-29 30-34 35-39 40-44 45-49 50-54 55-59 60-64 65-69 70-74

Frequency 5493 4640 4314 4554 4472 4264 3866 3264 2195 1330

Approximate the mean age. A) 50.0 B) 45.5

C) 48.0

D) 46.0

6) In a sample of adult women participating in the National Health and Nutrition survey,

74% of them were taller than 64.5 inches. On approximately what percentile is a woman who is 64.5 inches tall? A) 75th B) 27th C) 26th D) 74th 7) In Jacob’s statistics class, the final grade is a weighted mean of a homework grade, three

midterm exam grades, and a final exam grade. The homework counts for 10% of the final grade, each midterm counts for 20%, and the final exam counts for 30%. Jacob got a score of 70 on the homework, 59, 71, and 83 on the three midterms, and 78 on the final. What is Jacob’s final grade? A) 73 B) 70 C) 74 D) 72 8) A data set has a mean of 50 and a standard deviation of 10. Which of the following

might possibly be true? A) No less than 30% of the data values are less than 30 or greater than 70. B) More than 90% of the data values are between 20 and 80. C) At least 15% of the data values are less than 20 or greater than 80. D) No more than 50% of the data values are between 30 and 70. 9) A population has standard deviation 8. What is the population variance? A) 0.13

B) 16

C) 2.83

D) 64

10) The following TI-84 Plus display presents the five-number summary for a data set. Are

10)

there any outliers in this data set?

A) Yes

B) No

11) Use the given frequency distribution to approximate the mean.

Class 0-19 20-39 40-59 60-79 80-99 100-199 A) 46.8

11)

Frequency 16 13 4 5 9 5 B) 47.3

C) 8.7

D) 35.8

12) The ages of residents of a certain city are given in the following frequency distribution.

Class 0-9 10-19 20-29 30-39 40-49 50-59 60-69 70-79 80-89 90-99

Frequency 282 200 214 250 175 87 19 23 10 3

Approximate the mean age. A) 50 B) 12.6

C) 20.3

D) 27.9

12)

13) A National Center for Health Statistics study states that the mean height for adult men in

13)

the United States is 69.3 inches with a standard deviation of 3.4 inches, and the mean weight is 196.3 pounds with a standard deviation of 68.1 pounds. i. Compute the coefficient of variation for height. ii. Compute the coefficient of variation for weight. iii. Which has greater spread relative to its mean, height or weight? A) i. 20.382 B) i. 0.049 C) i. 20.382 D) i. 0.049 ii. 2.883 ii. 0.347 ii. 2.883 ii. 0.347 iii. Height iii. Height iii. Weight iii. Weight 14) Following are wind speeds (in mph) for 29 randomly selected days in San Francisco.

27.3 37.9 26.7 40.9

22.8 44.5 13.2 29.6

33.5 27.8 30.2 46.7

13.9 38.5 36.2 21.0

40.6 26.5 31.7 25.2

30.5 32.3 18.1

i. Are there any outliers? If so, list them. ii. Construct a boxplot for these data. iii. Describe the shape of this distribution. A) i. 13.2 ii.

iii. Skewed to the left B) i. No outliers ii.

iii. Skewed to the right

40.4 35.9 24.5

23.4 34.6 40.1

14)

C) i. 13.2

ii.

iii. Approximately symmetric D) i. No outliers ii.

iii. Approximately symmetric 15) For the years 1882–2019, the 87th percentile of annual snowfall in a certain city was 82.7

15)

inches. Approximately what percentage of years had snowfall less than 82.7 inches? A) 13% B) 12% C) 87% D) 86% 16) The table below presents the number of Executive Orders issued by U.S. presidents from

March 1861 through June 2019. President Abraham Lincoln Andrew Johnson Ulysses S. Grant Rutherford B. Hayes James Garfield Chester Arthur Grover Cleveland–I Benjamin Harrison Grover Cleveland–II William McKinley

Orders President 48 Theodore Roosevelt 79 William Howard Taf 217 Woodrow Wilson 92 Warren G. Harding 6 Calvin Coolidge 96 Herbert Hoover 113 Franklin D. Roosevelt 143 Harry S. Truman 140 Dwight D. Eisenhower 185 John F. Kennedy

Construct the five-number summary. A) 79, 143, 291, 724, 1203 C) 6, 143, 291, 724, 3721

Orders 1081 724 1803 522 1203 968 3721 907 484 214

President Lyndon Johnson Richard Nixon Gerald Ford Jimmy Carter Ronald Reagan George H. W. Bush William Clinton George W. Bush Barack Obama Donald Trump

B) 79, 140, 284, 522, 1203 D) 6, 140, 284, 522, 3721

Orders 325 346 169 320 381 166 364 291 277 114

16)

17) For which of the following histograms is it appropriate to use the Empirical Rule?

17)

D) all of these 18) A population has standard deviation 2.1. What is the population variance? A) 1.45

B) 0.48

C) 4.41

D) 4.20

18)

19) An article reported that the three quartiles for systolic blood pressure in a sample of 1213

19)

women between the ages of 20 and 29 were Q1 = 101, Q2 = 108, and Q3 = 114. i. Find the IQR. ii. Find the upper and lower outlier boundaries. iii. A systolic blood pressure greater than 145 is considered high. Would a blood pressure of 145 be an outlier? A) i. 7 B) i. 7 ii. 90.5; 111.5 ii. 90.5; 111.5 iii. No iii. Yes C) i. 13 D) i. 13 ii. 81.5; 133.5 ii. 81.5; 133.5 iii. No iii. Yes 20) The Energy Information Administration records the price of electricity in the United

20)

States each month. In one recent month, the average price of electricity was 11.35 cents per kilowatt-hour. Suppose that the standard deviation is 2.9 cents per kilowatt-hour. What can you determine about these data by using Chebyshev’s Inequality with K = 3? A) At least 75% between 2.65 and 20.05 cents B) At least 89.9% between 8.45 and 14.25 cents C) At least 75% between 8.45 and 14.25 cents D) At least 89.9% between 2.65 and 20.05 cents 21) Scores on a statistics exam had a mean of 75 with a standard deviation of 10. Scores on a

calculus exam had a mean of 60 with a standard deviation of 9. i. Compute the coefficient of variation for statistics exam scores. ii. Compute the coefficient of variation for calculus exam scores. iii. Which has greater spread relative to their mean, statistics scores or calculus scores? A) i. 8.556 B) i. 0.117 ii. 7.500 ii. 0.133 iii. Statistics scores iii. Statistics scores C) i. 0.117 D) i. 8.556 ii. 0.133 ii. 7.500 iii. Calculus scores iii. Calculus scores

21)

22) The three quartiles for systolic blood pressure in a sample of 3179 men were Q1 = 108,

22)

Q2 = 116, and Q3 = 127. i. Find the IQR. ii. Find the upper and lower outlier boundaries. iii. A systolic blood pressure greater than 140 is considered high. Would a blood pressure of 140 be an outlier? A) i. 19 B) i. 8 ii. 79.5; 155.5 ii. 96; 120 iii. No iii. Yes C) i. 19 D) i. 8 ii. 79.5; 155.5 ii. 96; 120 iii. Yes iii. No 23) In a recent year, 16% of players in the National Football League weighed less than 197

23)

pounds. On approximately what percentile is a player who weighs 197 pounds? A) 16th B) 84th C) 83rd D) 15th 24) Gina and Stewart are surf-fishing on the Atlantic coast, where both bluefish and

pompano are common catches. The mean length of a bluefish is 284 millimeters with a standard deviation of 39 mm. For pompano, the mean is 123 mm with a standard deviation of 34 mm. Stewart caught a bluefish that was 322 mm long, and Gina caught a pompano that was 176 mm long. Who caught the longer fish, relative to fish of the same species? A) Gina B) Stewart C) Neither. Relative to its respective species, the fish are the same length.

24)

25) Construct a boxplot for the data set below.

25)

26) The following data represent the ice cream flavor choices of 20 diners at a college

cafeteria.

Which flavor ice cream is the mode? A) Chocolate Chip C) Moose Tracks

B) Rocky Road D) Chocolate

26)

27) The following tables present the number of specimens that tested positive for Type A

27)

and Type B influenza in the United States during the first 15 weeks of a recent flu season. Type A influenza 39 96 168 407 559 1003 3933 4770 5159

231 1443 4851

288 2907 6480

Type B influenza 44 95 141 187 260 408 1710 1961 2077

203 555 2142

234 1368 2673

Find the median number of type A and type B cases in the first 15 weeks of the flu season. A) Type A: 2156 B) Type A: 1003 C) Type A: 1078 D) Type A: 1546 Type B: 937 Type B: 408 Type B: 469 Type B: 1546 28) Approximate the population standard deviation given the following frequency

28)

distribution. Class 0 - 14 15 - 29 30 - 44 45 - 59 60 - 74

Frequency 15 9 8 8 13

A) 545.6

B) 556.1

C) 23.6

D) 23.4

29) Following are heights, in inches, for a sample of college basketball players.

84 81

77 80

77 81

79 77

84 84

83 77

84 77

78 82

80 82

81 79

Find the mean height of the basketball players. A) 80.5 inches B) 6.6 inches C) 70 inches

D) 80.4 inches

29)

30) The completion times for a certain marathon race was 2.4 hours with a standard

30)

deviation of 0.5 hours. What can you determine about these data by using Chebyshev's Inequality with K = 2? A) No more than 75% of the completion times are between 1.4 hours and 3.4 hours. B) At least 75% of the completion times are between 1.4 hours and 3.4 hours. C) At least 88.9% of the completion times are between 1.4 hours and 3.4 hours. D) At most 88.9% of the completion times are between 1.4 hours and 3.4 hours. 31) The following data represent the total price, in dollars, of 20 randomly-selected gasoline

31)

purchases at a certain convenience store.

Find the mean price for these purchases. A) $35.88 B) $41.88

C) $37.40

D) $130.84

32) Find the mode for the following data set:

16 A) 20

36 B) 27.2

32)

27 C) 26

D) 26.5

33) For the data set below, find the upper outlier boundary.

166 174 A) 247.5

175

183 188 B) 232.5

190

197 204 C) 131.5

33)

209

253 D) 253

34) Elizabeth worked at three part-time jobs last week. At one job, she worked 5 hours at a

34)

salary of $12 per hour, at the second she worked 15 hours at $10 per hour, and at the third she worked 20 hours at $15 per hour. What was her mean hourly wage? A) $40.00 B) $12.75 C) $12.33 D) $13.78 35) For the data set below, find the IQR.

A) 10

35)

B) 64

C) 17

D) 74

36) Approximate the sample variance given the following frequency distribution.

Class 0-9 10 - 19 20 - 29 30 - 39 40 - 49

36)

Frequency 10 17 12 14 11

A) 13.5

B) 182.5

C) 13.4

D) 179.7

37) For the data set below, find the outlier(s).

37)

A) 189

B) 141 and 150

C) 141 and 189

D) None are outliers.

38) Gina and Stewart are surf-fishing on the Atlantic coast, where both bluefish and

38)

pompano are common catches. The mean length of a bluefish is 285 millimeters with a standard deviation of 54 mm. For pompano, the mean is 128 mm with a standard deviation of 24 mm. Stewart caught a bluefish that was 313 mm long. What was the z-score for this length? A) 0.52 B) 313 C) 7.71 D) 5.8 39) Find the mode of the data in the following stem-and-leaf plot. The leaf represents the

39)

ones digit.

A) 13.3

B) 11.2

C) 12.3

D) 14

40) Following are the closing prices (in dollars) of a certain stock for the past 20 trading

days. 149.54 131.62 132.99 144.42 132.58 133.24 135.52 139.78 152.12 134.13 126.81 131.94 133.29 142.06 156.96 139.56 125.11 158.80 129.80 144.99 Find the population standard deviation for the closing prices. A) $138.76 B) $9.68 C) $33.69 12

D) $9.44

40)

41) Find the population variance for the following data set:

41)

27 13 28 32 20 A) 56.5

B) 7.5

C) 19

D) 45.2

42) Find the sample variance for the following data set:

42)

23 14 32 29 17 A) 7.6

B) 18

C) 58.5

D) 46.8

43) The following population parameters were obtained from a graphing calculator.

43)

x=56 x=616 x2 =34496 Sx=13.634515 x=13 n=11 Assuming the population is bell-shaped, between what two values will approximately 95% of the population be? A) 17 to 95 B) 56 to 95 C) 30 to 82 D) 43 to 69 44) The mean salary of professional baseball players is $2.58 million with a standard

44)

deviation of 0.33. A new player is hired with a salary of $2.76 million. What is the z-score of this salary? A) 8.36 B) -16.18 C) 16.18 D) 0.55 45) For the data set below, find the third quartile.

A) 52.5

45)

B) 75

C) 66

D) 60

46) The table below lists the populations, in thousands, of several rural western counties.

46)

What is the median population? County Population (thousands) Aldridge 13 Cleveland 8 McCarthy 16 Pope 18 Sorrell 14 Wilson 20 A) 12 thousand

B) 14 thousand

C) 15 thousand

D) 14.8 thousand

47) For the data set below, find the first quartile.

A) 76

47)

B) 48.5

C) 60

D) 65

48) A survey found that the median number of calories consumed per day in a certain

48)

country was 3304 and the mean was 3204.9 calories. If a histogram were constructed for the data, would you expect it to be skewed to the right, to the left, or approximately symmetric? A) skewed to the right B) approximately symmetric C) skewed to the left 49) Find the mean for the following data set:

21 A) 16

24 B) 18

49)

13 C) 19.2

D) 13

50) A soft-drink bottling company fills and ships soda in plastic bottles with a target volume

50)

of 354 milliliters. The filling machinery does not deliver a perfectly consistent volume of liquid to each bottle, and the three quartiles for the fill volume are Q 1 = 351, Q 2 = 357, and Q 3 = 360. Find the IQR. A) 9

B) 13.5

C) 3

D) 10.8

51) Find the median for the following data set:

17 A) 16.4

24 B) 17

51)

10 C) 10 14

D) 14

52) For the data set below, find the 37th percentile.

A) 46

B) 48.5

52)

C) 37

D) 36

53) For the data shown in the histogram, which of the following choices best describes the

53)

relationship between the median and the mean?

A) median < mean

B) median > mean

C) median

54) A population has a mean

= 17 and standard deviation

= 14. What number has a

z-score of -0.1? A) -1.2

B) -18.4

C) 15.6

mean

D) -1.4

55) Find the mean for the following data set:

18 A) 21.5

21 B) 4.0

55)

16 C) 12

D) 21.7

56) Find the mode for the following data set:

32 A) 20

26 B) 20.8

54)

56)

13 C) 13

D) 19

57) Use the given frequency distribution to approximate the mean.

Class 0 – 19 20 – 39 40 – 59 60 – 79 80 – 99 A) 48.7

57)

Frequency 19 17 12 12 19 B) 30.2

C) 30.4

D) 15.8

58) The following table presents the number of monthly users for the 7 most popular mobile

58)

apps. Application Facebook YouTube Facebook Messenger Google Search Google Play Google Maps Pandora Radio

Monthly Users (millions) 121.1 97.2 95.5 81.6 77.0 75.5 73.9

Find the mean number of monthly users. A) 103.6 B) 88.8

C) 621.8

D) 81.6

59) Approximate the sample standard deviation given the following frequency distribution.

Class 0 - 19 20 - 39 40 - 59 60 - 79 80 - 99 A) 28.5

Frequency 10 18 10 8 13 B) 28.3

C) 811.9

D) 798.2

59)

60) Find the median of the data in the following stem-and-leaf plot. The leaf represents the

60)

ones digit.

A) 25.9

B) 22

C) 26

D) 28.6

61) The following table presents the heights (in inches) of a sample of college basketball

61)

players. Height (in.) 68 - 71 72 - 75 76 - 79 80 - 83 84 - 87

Frequency 2 2 4 2 3

Considering the data to be a population, approximate the variance of the heights. A) 5.4 B) 29.2 C) 5.6 D) 31.6 62) The following data represent the total price, in dollars, of 20 randomly-selected gasoline

62)

purchases at a certain convenience store.

Find the median price for these purchases. A) $130.84 B) $37.40

C) $35.88

D) $41.88

63) Find the median for the following data set:

13 A) 15

26 B) 20

63)

18 C) 18.8

D) 5.4

64) A report states that the mean household income last year for a certain rural county was

$46,200 and the median was $37,800. If a histogram were constructed for the incomes of all households in the county, would you expect it to be skewed to the right, to the left, or approximately symmetric? A) skewed to the left B) approximately symmetric C) skewed to the right 17

64)

65) A botany student measured the lengths of a sample of leaves to the nearest centimeter.

65)

The data is shown in the frequency distribution below. Use the data to approximate the mean to the nearest tenth of a centimeter. Length 0-5 6-11 12-17 18-23 24-29 30-35

Frequency 4 7 13 18 8 5

A) 5.8 cm

B) 9.2 cm

C) 18.2 cm

D) 18.7 cm

66) A data set has a median of 63, and six of the numbers in the data set are less than

66)

median. The data set contains a total of n numbers. If n is even, and none of the numbers in the data set are equal to 63, what is the value of n? A) 10 B) 16 C) 13 D) 12 67) Following are heights, in inches, for a sample of college basketball players.

67)

70 78 70 75 75 72 76 85 88 84 84 71 85 81 78 88 71 70 76 88 Find the sample standard deviation for the heights of the basketball players. A) 6.4 B) 78.3 C) 6.6 D) 18 68) Find the median for the following data set:

12 A) 16.6

15 B) 11

68)

23 C) 15

D) 4.2

69) Find the median for the following data set:

28 A) 23.7

29 B) 26

69)

14 C) 19

D) 14

70) A consumer advocacy group tested the "on-air" lifetimes of a random sample of 148 cell

70)

phone batteries. The mean lifetime was 2.7 hours with a standard deviation of 0.2 hours. The lifetimes are approximately bell-shaped. Estimate the number of batteries with lifetimes between 2.3 hours and 3.1 hours. A) 101 B) 141 C) almost all (greater than 141) D) 7 71) A data set has a median of 64, and six of the numbers in the data set are less than

71)

median. The data set contains a total of n numbers. If n is odd, and exactly one number in the data set is equal to 64, what is the value of n? A) 17 B) 13 C) 16 D) 15 72) The following tables present the number of specimens that tested positive for Type A

72)

and Type B influenza in the United States during the first 15 weeks of a recent flu season. Type A influenza 40 94 192 396 572 969 3876 4717 5293

210 1406 5229

288 2850 6723

Type B influenza 47 96 138 187 273 374 1596 2014 2077

182 555 2079

216 1311 2673

Find the mean number of type A and type B cases in the first 15 weeks of the flu season. A) Type A: 2190 B) Type A: 1095 C) Type A: 1556 D) Type A: 969 Type B: 921 Type B: 461 Type B: 1556 Type B: 374 73) For the data set below, find the third quartile.

166 168 A) 183.5

177

181 186 B) 194

73)

188

194 201 C) 177

209

251 D) 201

74) In Steve's statistics class, the final grade is a weighted mean of a homework grade, three

midterm grades, and a final exam grade. The homework counts for 10% of the grade, each midterm counts for 20%, and the final exam counts for 30%. Steve got an average score of 80 on the homework, 70, 80, and 80 on the midterms, and 70 on the final. What is Steve's final grade? A) 31 B) 77 C) 75 D) 76

74)

75) Construct a boxplot for the data set below.

75)

76) Approximate the population variance given the following frequency distribution.

Class 0 - 14 15 - 29 30 - 44 45 - 59 60 - 74 A) 20.5

Frequency 12 16 15 9 11 B) 419.9

C) 20.3

D) 413.3

76)

77) A data set contains three unique values. Which of the following must be true? A) mean = median = midrange

B) mean = median

C) none of these

D) median = midrange

78) A student has an average of 79 on seven chapter tests. If the student's scores on six of the

77)

78)

tests are 77, 73, 87, 67, 80, and 71, what was the score on the remaining test? A) 79 B) 90 C) 98 D) 76 79) Find the mean for the following data set:

15 A) 7.0

20 B) 25.2

79)

26 C) 19

D) 26

80) Find the mean for the following data set:

A) 11

18 B) 14

80)

25 C) 17.2

D) 18

81) Find the population standard deviation for the following data set:

81)

36 16 31 17 24 A) 8.7

B) 75.7

C) 7.8

D) 60.6

82) The following table presents the heights (in inches) of a sample of college basketball

players. Height (in.) 68 - 71 72 - 75 76 - 79 80 - 83 84 - 87

Frequency 17 40 62 40 18

Considering the data to be a population, approximate the standard deviation of the heights. A) 78 B) 19.9 C) 4 D) 4.5

82)

83) The table below lists the populations, in thousands, of several rural western counties.

83)

What is the mean population? County Population (thousands) Aldridge 10 Cleveland 14 McCarthy 18 Pope 11 Sorrell 17 Wilson 9 A) 13.2 thousand

B) 9 thousand

C) 12.5 thousand

D) 13.5 thousand

84) Addison has been told that her average on six homework assignments in her history class

84)

is 93. She can find only five of the six assignments, which have scores of 90, 97, 98, 88, and 98. What is the score on the lost homework assignment? A) 87 B) 84 C) 88 D) 85 85) Find the sample standard deviation for the following data set:

85)

22 13 34 27 18 A) 52.6

B) 7.2

C) 65.7

D) 8.1

86) The following table presents the number of monthly users for the 7 most popular mobile

apps. Application Facebook YouTube Facebook Messenger Google Search Google Play Google Maps Pandora Radio

Monthly Users (millions) 124.5 103.4 94.9 84.1 78.1 75.8 73.7

Find the median number of monthly users. A) 634.5 B) 105.8

C) 90.6

D) 84.1

86)

87) Find the mean of the data in the following stem-and-leaf plot. The leaf represents the

87)

ones digit.

A) 28.6

B) 27

C) 22

D) 26

88) A study found that the mean amount of time that people in the United States spent

88)

watching TV was 108.1 hours per year. The same study found that the median was 109.2 hours per year. If a histogram were constructed for the data, would you expect it to be skewed to the right, to the left, or approximately symmetric? A) approximately symmetric B) skewed to the right C) skewed to the left 89) The following population parameters were obtained from a graphing calculator.

89)

x=71 x=852 x2 =60492 Sx=10.4446594 x=10 n=12 Assuming the population is bell-shaped, approximately what percentage of the population values are between 51 and 91? A) almost all (greater than 95%) B) 68% 5% C) D) 95% 90) For the data set below, find the outlier(s).

210 172 252 A) 202 and 210 C) 252

183

90)

179

191 197 169 202 B) 202 D) None are outliers.

91) A paint manufacturer discovers that the mean volume of paint in a gallon-sized pail is

91)

1.1 gallons with a standard deviation of 0.1 gallons. The paint volumes are approximately bell-shaped. Estimate the percent of pails with volumes between 1.00 gallon and 1.20 gallons. A) 68% B) almost all (greater than 95%) C) 95% D) 32% 92) A data set has a mean of 157 and a standard deviation of 20. Compute the coefficient of

variation. A) 0.13

B) 2.55

C) 7.69

92)

D) 20.00

93) The mean systolic blood pressure for a sample of 500 individuals is 110 with a standard

93)

deviation of 16. A patient's systolic blood pressure is measured at 84. What is the z-score for this measurement? A) 1.62 B) -1.62 C) 26.00 D) -26 94) A population has a mean

population value of 13. A) -0.5

= 46 and standard deviation B) -2.2

94)

= 15. Find the z-score for a

C) -33

D) 0.9

95) A soft-drink bottling company fills and ships soda in plastic bottles with a target volume

95)

of 354 milliliters. The filling machinery does not deliver a perfectly consistent volume of liquid to each bottle, and the three quartiles for the fill volume are Q 1 = 349, Q 2 = 352, and Q 3 = 355. A fill volume of 345 mL is considered low. Would a fill volume of 345 mL be considered an outlier? A) Yes B) No 96) For the data set below, find the first quartile.

169 173 A) 186.5

179

185 188 B) 195

96)

192

195 204 C) 204

208

251 D) 179

97) The following data represent the total price, in dollars, of 20 randomly-selected gasoline

purchases at a certain convenience store. 53.00 61.49

64.69 45.76

46.33 80.00

72.14 79.06

56.86 41.75

67.91 59.91

47.89 49.06

66.10 52.85

61.80 46.98

Which value in this data set is most accurately described as an extreme value? A) $80.00 B) $10.42 C) $69.58 D) $53.00

44.33 10.42

97)

98) For the data set below, find the IQR.

167 A) 83

171

175

183 B) 21

188

98)

188

193 200 25 C)

209

250 D) 18

99) For the data set below, list the outliers, if any.

99)

A) 82 and 83

B) 11, 82, and 83

C) 83

D) There are no outliers.

100) For the data set below, find the upper outlier boundary.

A) 45

B) 195

C) 243.5

100)

D) 176

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 101) The five-number summary consists of the minimum, the first quartile, the mode, the

101)

third quartile, and the maximum. 102) Chebyshev’s Inequality states that for any data set, the proportion of data within K

standard deviations of the mean is at least 1 -

1 K2

102)

103) For some data sets, Chebyshev’s Inequality may be used but the Empirical Rule should

103)

not be. 104) The variance and standard deviation are measures of center.

104)

105) The range of a data set is the difference between the largest value and the smallest value.

105)

106) The 25th percentile is the same as the first quartile.

106)

Answer Key Testname: C3

1) C 2) A 3) A 4) B 5) D 6) D 7) A 8) B 9) D 10) A 11) B 12) D 13) D 14) D 15) C 16) D 17) A 18) C 19) D 20) D 21) C 22) A 23) A 24) A 25) B 26) D 27) B 28) D 29) D 30) B 31) A 32) C 33) A 34) B 35) A 36) B 37) C 38) A 39) D 40) D 41) D 42) C 43) C 44) D 45) B 46) C 47) D 48) B 49) C 50) A 26

Answer Key Testname: C3

51) B 52) A 53) C 54) C 55) D 56) C 57) A 58) B 59) A 60) C 61) B 62) D 63) B 64) C 65) D 66) D 67) C 68) C 69) B 70) B 71) B 72) A 73) D 74) C 75) A 76) D 77) C 78) C 79) B 80) C 81) C 82) D 83) A 84) A 85) D 86) D 87) A 88) A 89) D 90) C 91) A 92) A 93) B 94) B 95) B 96) D 97) B 98) C 99) A 100) C 27

Answer Key Testname: C3

101) FALSE 102) TRUE 103) TRUE 104) FALSE 105) TRUE 106) TRUE

Exam Name___________________________________

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) When growing giant pumpkins for competitions, growers need to keep track of the

weights of the pumpkins while they are growing. It is difficult to weigh a large pumpkin before it is harvested, so a method has been developed for estimating the weight. The grower measures around the pumpkin both horizontally and vertically, then adds the results. This is called the OTT (over the top) measurement and is used to predict the weight of the pumpkin. Following are the OTT measurements and actual weights of the 20 largest pumpkins entered into official competitions in the year 2018. OTT (inches) 490.0 469.0 490.0 480.0 455.0 463.0 473.0 477.0 465.0 454.0

Weight (pounds) 2528.0 2469.0 2433.9 2416.5 2283.0 2170.0 2166.0 2157.5 2152.0 2138.9

OTT (inches) 465.0 452.0 451.0 456.0 457.0 456.0 462.0 436.0 454.0 450.0

Weight (pounds) 2138.0 2136.0 2114.0 2091.0 2079.0 2077.0 2070.1 2027.0 2020.5 2017.5

i. Compute the least-squares regression line for predicting weight (y) from OTT (x). ii. Construct a residual plot. Does the relationship appear to be approximately linear? ^

A) i. y = -1884.6 + 8.9193x

B) i. y = -1884.6 + 8.9193x

ii. No

ii. Yes

C) i. y = -1917.1 + 8.8629x

D) i. y = -1917.1 + 8.8629x

ii. Yes

ii. No

2) For the following data set:

x 9 5 6 14 -8 -3 7 -11 y 3 2 31 37 2 4 -1 -14 i. Compute the coefficient of determination. ii. How much of the variation in the outcome variable is explained by the least-squares regression line? A) i. 0.457 B) i. 0.676 C) i. 0.457 D) i. 0.676 ii. 54.3% ii. 32.4% ii. 45.7% ii. 67.6%

3) In a sample of adults, would the correlation between age and year graduated from high

school be closest to -1, -0.5, 0, 0.5, or 1? A) -0.5 B) -1 C) 0

D) 1

E) 0.5

4) State the type of association that is exhibited in the following scatterplot.

A) Negative linear

B) Negative nonlinear

C) Positive linear

D) Positive nonlinear

5) The following table presents the number of police officers (per 100,000 citizens) and the

annual murder rate (per 100,000 citizens) for a sample of cities.

The correlation coefficient between the per capita number of police officers and the per capita murder rates -0.899. Which of the following is the best interpretation of the correlation coefficient? A) Higher murder rates make it more difficult for cities to hire police officers. B) More per capita police officers results in fewer per capita murders. C) The per capita number of police officers and the per capita murder rates are positively associated. D) The per capita murder rate tends to go down as the per capita number of police officers goes up.

6) State the type of association that is exhibited in the following scatterplot.

A) Positive linear

B) Negative linear

C) Positive nonlinear

D) Negative nonlinear

7) State the type of association that is exhibited in the following scatterplot.

A) Positive linear

B) Positive nonlinear

C) Weak linear

D) Negative linear

8) The National Assessment for Educational Progress (NAEP) is a U.S. government

organization that assesses the performance of students and schools at all levels across the United States. The following table presents the percentage of eighth-grade students who were found to be proficient in mathematics, and the percentage who were found to be proficient in reading in each of the 10 most populous states.

State California Texas New York Florida Illinois Pennsylvania Ohio Michigan Georgia North Carolina

Percentage Proficient in Reading 60 71 75 65 73 79 81 74 65 71

Percentage Proficient in Mathematics 61 79 69 67 72 76 78 67 62 72

Compute the correlation between reading proficiency and math proficiency. Is the linear association positive or negative? Weak or strong? A) r = 0.769; positive; strong B) r = -0.231; negative; weak C) r = 0.769; positive; weak D) r = -0.231; positive; strong 9) A sample of adults was studied to determine the relationship between education level

and annual income. The least-squares regression line for predicting income from ^

education level was computed to be y = 2888 + 3326x, where x is the number of years of education and y is the predicted annual income. The number of years of education among the people in the sample ranged from 8 to 18. If possible, use the least-squares regression line to predict the annual income of a person with 11 years of education. A) $46,126 B) $39,474 C) $42,800 D) Not possible 10) In a sample of adults, would the correlation between year of birth and year graduated

from high school be closest to -1, -0.5, 0, 0.5, or 1? A) 1 B) -0.5 C) -1

D) 0.5

E) 0

10)

11) For the following plot, is it possible to interpret the y-intercept?

11)

The least-squares regression line is y = 1.98 + 0.039x, where x is the temperature in a freezer in degrees Fahrenheit, and y is the time it takes to freeze a certain amount of water into ice. A) Not possible B) Possible 12) MINITAB-style residual plots are shown below. Which one of these plots indicates that

it was appropriate to compute a least-squares regression line? A)

12)

13) For the following plot, interpret the y-intercept of the least-squares regression line if

possible.

The least-squares regression line is y = -13.586 + 4.340x, where x represents the age of an elementary school student and y represents the score on a standardized test. A) Not possible B) Possible

13)

14) In each of the following plots, one point is an outlier. The blue solid line is the

14)

least-squares regression line computed without using the outlier, and the red dashed line is the least-squares regression line computed by including the outlier. State whether the outlier is influential.

A) Influential

B) Not influential

15) For the following data set:

15)

x 73 86 25 3 52 45 52 y 62 66 41 21 33 37 47 i. Compute the least-squares regression line. ii. Which point is an outlier? iii. Remove the outlier and compute the least-squares regression line. iv. Is the outlier influential? Explain. ^

A) i. y = 19.2354 + 0.5123x

B) i. y = 19.3734 + 0.5101x

ii. (3, 21)

iii. y = 19.3734 + 0.5101x iv. No

iii. y = 19.2354 + 0.5123x iv. No

C) i. y = 19.3734 + 0.5101x

D) i. y = 19.2354 + 0.5123x

ii. (3, 21)

iii. y = 19.2354 + 0.5123x iv. Yes

iii. y = 19.9619 + 0.5791x iv. Yes

16) MINITAB-style residual plots are shown below. Which one of these plots indicates that

it was appropriate to compute a least-squares regression line? A)

16)

17) Do larger butterflies live longer? The wingspan (in millimeters) and the lifespan in the

adult state (in days) were measured for 22 species of butterfly. Following are the results. Wingspan 35.5 30.6 30.0 32.3 23.9 27.7 28.8 35.9 25.4 24.6 28.1

Lifespan 19.8 17.3 27.5 22.4 40.7 18.3 25.9 23.1 24.0 38.8 36.5

Wingspan 25.9 31.3 23.0 26.3 23.7 27.1 28.1 25.9 28.8 31.4 28.5

Lifespan 32.5 27.5 31.0 37.4 22.6 23.1 18.5 32.3 29.1 37.0 33.7

i. If the wingspans of two butterflies differ by 3 millimeters, by how much would you predict their lifespans to differ? ii. Predict the lifespan for a butterfly whose wingspan is 28.1 millimeters. A) i. -0.8445 B) i. -0.8445 C) i. 2.534 D) i. 2.534 ii. 26.91 ii. 28.31 ii. 26.91 ii. 28.31

17)

18) State the type of association that is exhibited in the following scatterplot.

A) Weak linear

B) Positive nonlinear

C) Positive linear

D) Negative linear

19) One of the primary feeds for beef cattle is corn. The following table presents the average

price in dollars for a bushel of corn and a pound of ribeye steak for 10 consecutive months.

The correlation coefficient between the corn price and the ribeye price is 0.785. Which of the following is the best interpretation of the correlation coefficient? A) The price of ribeye tends to go down and the price of corn goes up. B) Increasing corn prices cause ribeye prices to increase. C) The changes in corn price and ribeye price tend to go up and down together. D) There is no correlation between the price of corn and the price of ribeye.

18)

19)

20) For the following data set:

20)

x 3.9 5.8 4.8 3.3 1.8 3.4 3.2 y 4.6 4.1 5.2 4.5 9.2 5.6 4.3 i. Compute the least-squares regression line. ii. Which point is an outlier? iii. Remove the outlier and compute the least-squares regression line. iv. Is the outlier influential? Explain. ^

A) i. y = 8.7023 + 0.9431x

B) i. y = 8.9888 + 0.9703x

ii. (1.8, 9.2)

iii. y = 5.3289 - 0.1413x iv. Yes

iii. y = 5.2915 - 0.1413x iv. No

C) i. y = 8.7023 + 0.9431x

D) i. y = 8.9888 + 0.9703x

ii. (1.8, 9.2)

iii. y = 5.3289 - 0.1413x iv. No

iii. y = 5.2915 - 0.1413x iv. Yes

21) In each of the following plots, one point is an outlier. The blue solid line is the

A) Influential

B) Not influential

21)

22) Do larger butterflies live longer? The wingspan (in millimeters) and the lifespan in the

adult state (in days) were measured for 22 species of butterfly. Following are the results. Wingspan 35.5 30.6 30.0 32.3 23.9 27.7 28.8 35.9 25.4 24.6 28.1

Lifespan 19.8 17.3 27.5 22.4 40.7 18.3 25.9 23.1 24.0 38.8 36.5

Wingspan 25.9 31.3 23.0 26.3 23.7 27.1 28.1 25.9 28.8 31.4 28.5

Lifespan 32.5 27.5 31.0 37.4 22.6 23.1 18.5 32.3 29.1 37.0 33.7

i. Compute the least-squares regression line for predicting the lifespan from the wingspan. ii. Is it possible to interpret the y-intercept? ^

A) i. y = 52.0434 - 0.8445x

B) i. y = 52.0434 - 0.8445x

ii. Yes

ii. No

C) i. y = 51.1389 - 0.8621x

D) i. y = 51.1389 - 0.8621x

ii. Yes

ii. No

22)

23) A blood pressure measurement consists of two numbers: the systolic pressure, which is

23)

the maximum pressure taken when the heart is contracting, and the diastolic pressure, which is the minimum pressure taken at the beginning of the heartbeat. Blood pressures were measured, in millimeters of mercury (mmHg), for a sample of 16 adults. The following table presents the results. Systolic 134 115 113 123 119 118 130 116

Diastolic 87 83 77 77 69 88 76 70

Systolic 133 112 107 110 108 105 157 154

Diastolic 91 75 71 74 69 66 103 94

i. If the systolic pressures of two patients differ by 10 mmHg, by how much would you predict their diastolic pressures to differ? ii. Predict the diastolic pressure for a patient whose systolic pressure is 125 mmHg. A) i. 6.186 B) i. 5.748 C) i. 5.748 D) i. 6.186 ii. 86.1 ii. 86.1 ii. 81.0 ii. 81.0 24) For which of the following scatter plots is the correlation coefficient an appropriate

summary? A)

24)

25) For the following data set:

25)

x 1 2 3 4 5 y 5 6 9 8 8 i. Compute the coefficient of determination. ii. How much of the variation in the outcome variable is explained by the least-squares regression line? A) i. 0.77 B) i. 0.59 C) i. 0.77 D) i. 0.59 ii. 23% ii. 41% ii. 77% ii. 59% 26) Following is a residual plot produced by MINITAB. Was it appropriate to compute the

least-squares regression line?

A) No

B) Yes

26)

27) Following are average temperatures, in degrees Fahrenheit, during the months of January

27)

and July for 15 U.S. cities.

City Albuquerque Atlanta Boston Chicago Cleveland Denver Detroit Houston Indianapolis Minneapolis New Orleans New York Salt Lake City St. Louis Washington, D.C.

January Temperature 35.7 42.7 29.3 22.0 25.7 29.2 24.5 51.8 26.5 13.1 52.6 32.1 29.2 29.6 34.9

July Temperature 78.5 80.0 73.9 73.3 71.9 73.4 73.5 83.6 75.4 73.2 82.7 76.5 77.0 80.2 79.2

i. Compute the least-squares regression line for predicting July temperature from January temperature. ii. Construct a residual plot. Does the relationship appear to be approximately linear? ^

A) i. y = 66.8914 + 0.2874x

B) i. y = 67.0556 + 0.3058x

ii. Yes

ii. No

C) i. y = 67.0556 + 0.3058x

D) i. y = 66.8914 + 0.2874x

ii. Yes

ii. No

28) As with many other construction materials, the price of gravel (per ton) depends on the

quantity of material ordered. The following table presents the unit cost (dollars/ton) for gravel for various order sizes (in tons).

Which of the following graphs is the correct residual plot for the data set? (Hint: create your own residual plot and compare it to those shown below.) 16

28)

29) Following is a residual plot produced by MINITAB. Was it appropriate to compute the

least-squares regression line?

A) Yes

B) No

29)

30) A blood pressure measurement consists of two numbers: the systolic pressure, which is

30)

Diastolic 87 83 77 77 69 88 76 70

Systolic 133 112 107 110 108 105 157 154

Diastolic 91 75 71 74 69 66 103 94

i. Compute the least-square regression line for predicting the diastolic pressure from the systolic pressure. ii. Is it possible to interpret the y-intercept? ^

A) i. y = 8.7254 + 0.6186x

B) i. y = 9.1828 + 0.5748x

ii. No

C) i. y = 9.1828 + 0.5748x

D) i. y = 8.7254 + 0.6186x

ii. Yes

31) A sample of adults was studied to determine the relationship between education level

31)

and annual income. The least-squares regression line for predicting income from ^

education level was computed to be y = 2790 + 3319x, where x is the number of years of education and y is the predicted annual income. The number of years of education among the people in the sample ranged from 8 to 18. If possible, use the least-squares regression line to predict the annual income of a person with 5 years of education. A) $16,066 B) $26,023 C) $19,385 D) Not possible

32) Following is a residual plot produced by MINITAB. Was it appropriate to compute the

32)

least-squares regression line?

A) No

B) Yes

33) State the type of association that is exhibited in the following scatterplot.

A) Negative nonlinear

B) Positive nonlinear

C) Negative linear

D) Weak linear

33)

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. 34) Making predictions for values of the explanatory variable that are outside of the

range of the data is called

34)

35) An outlier that strongly affects the position of a least-squares regression line is

said to be 36) A

35)

. is the difference between an observed value and a predicted value of

36)

the outcome variable. 37) The least-squares property says that the

is smaller for the least-squares

37)

regression line than for any other line. MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 38) The following table presents the number of police officers (per 100,000 citizens) and the

annual murder rate (per 100,000 citizens) for a sample of cities.

Construct a scatter plot of the per capita murder rate (y) versus the per capita number of police officers (x). A)

38)

39) Characterize the relationship shown in the figure.

A) positive linear

B) negative nonlinear

C) positive nonlinear

D) negative linear

40) The common cricket can be used as a crude thermometer. The colder the temperature,

39)

40)

the slower the rate of chirping. The table below shows the average chirp rate of a cricket at various temperatures. Chirp Rate (chirps/second) 2.8 1.7 3.3 2.7 2.3 3.4

Temperature (°F) 70.5 54.7 71.6 69 54.1 73.1

The least-squares regression line for predicting the temperature from the chirp rate is y = 32.298 + 12.297x. If two chirp rates differ by 1.5 chirps per second, by how much would the temperature differ? A) 48 ºF B) 18 ºF C) 17 ºF D) 21 ºF 41) An automotive engineer computed a least-squares regression line for predicting the gas

mileage (mile per gallon) of a certain vehicle from its speed in mph. The results are presented in the following Excel output.

Intercept Speed

Coefficients 38.3949789 -0.18832886

Write the equation of the least-squares regression line. A) y = 38.3949789 + 0.18832886x B) y = -0.18832886 + 38.3949789x C) y = -38.394979 + 0.18832886x D) y = 38.3949789 - 0.18832886x 23

41)

42) The common cricket can be used as a crude thermometer. The colder the temperature,

42)

the slower the rate of chirping. The table below shows the average chirp rate of a cricket at various temperatures. Chirp Rate (chirps/second) 1.9 2.7 2.8 1.4 1.7 3.0

Temperature (°F) 47.7 67.7 65.4 42.8 54.7 63.3

The least-squares regression line for predicting the temperature from the chirp rate is y = 25.6974 + 13.8826x. Predict the temperature if the chirp rate is 1.6 chirps per second. A) 48 ºF B) 22 ºF C) 51 ºF D) 44 ºF 43) Of points 1, 2, and 3 shown below, which is the most influential?

A) point 2

B) All have the same influence.

C) point 1

D) point 3

43)

44) One of the primary feeds for beef cattle is corn. The following table presents the average

44)

price in dollars for a bushel of corn and a pound of ribeye steak for 10 consecutive months.

Compute the correlation coefficient between the corn price and the ribeye price. A) 0.181 B) 0.819 C) 0.671 D) 0.719 45) Compute the correlation coefficient.

x y

5 108

A) 0.779

6 102

7 113

8 116

9 153

45)

10 149

B) 0.117

C) 46.143

D) 0.883

46) A blood pressure measurement consists of two numbers: the systolic pressure, which is

46)

the maximum pressure taken when the heart is contracting, and the diastolic pressure, which is the minimum pressure taken at the beginning of the heartbeat. Blood pressures were measured, in millimeters of mercury (mmHg), for a sample of eight adults. The following table presents the results. Systolic 127 125 135 110 123 121 118 127

Diastolic 92 94 87 75 89 87 87 93

The least-squares regression equation is y = 18.7841 + 0.5616x. If the systolic pressures of two patients differ by 8 mmHg, by how much would you predict their diastolic pressures to differ? A) 0.56 mmHg B) 4.49 mmHg C) 8.56 mmHg D) 0.07 mmHg 47) The following display from a graphing calculator presents the least-squares regression

line for predicting the price of a certain commodity (y) from the price of a barrel of oil (x).

y = a+bx a = 4.95 b = 0.29 r2 = 0.53045 r = 0.72832

Predict the commodity price when oil costs $107 per barrel. A) $36 B) $62 C) $83

D) $530

47)

48) The following MINITAB output presents the lest squares regression line for predicting

48)

the price of a certain commodity from the price of a barrel of oil. The regression equation is Commodity = 98.534563 + 0.940332 Oil Predictor Constant Oil

Coef 98.534563 0.940332

SE Coef 38.540569 0.377387

T 2.556645 2.491694

P 0.062862 0.067363

Predict the commodity price when the oil price is $105 per barrel. A) $197 B) $217 C) $99

D) $187

49) The common cricket can be used as a crude thermometer. The colder the temperature,

49)

the slower the rate of chirping. The table below shows the average chirp rate of a cricket at various temperatures. Chirp Rate (chirps/second) 3.7 2.6 1.9 1.8 3.9 2.8

Temperature (°F) 67.8 64.6 55.1 44.3 71 67.8

Compute the least-squares regression line for predicting the temperature from the chirp rate. A) y = 34.0748 + 12.7143x B) y = 12.7143 + 34.0748x C) y = 34.0748 + 9.9492x D) y = 9.9492 + 34.0748x 50) An automotive engineer computed a least-squares regression line for predicting the gas

mileage (miles per gallon, or mpg) of a certain vehicle from its speed in mph. The results are presented in the following Excel output.

Intercept Speed

Coefficients 38.5176991 -0.19495575

Predict the gas mileage when the vehicle is traveling at 56 mph. A) 25.2 mpg B) 28 mpg C) 31 mpg

D) 49 mpg

50)

51) For the following data set, how much of the variation in the outcome variable is

51)

explained by the least-squares regression line? x y

1 7

3 18

2 5

A) 48.1%

8 13

9 15

5 9

B) 26.9%

C) 51.9%

D) 73.1%

52) One of the primary feeds for beef cattle is corn. The following table presents the average

52)

price in dollars for a bushel of corn and a pound of ribeye steak for 10 consecutive months. Corn Price ($/bu) 5.97 6.37 5.92 5.91 5.79 6.35

Ribeye Price ($/lb) 12.20 12.86 12.51 12.28 12.67 13.13

The least-squares regression line for predicting the ribeye price from the corn price is y = 6.3662 + 1.0315x. If the price of corn differs by $0.15 per bushel, by how much would you expect the price of ribeye to differ? A) $0.95 per lb B) -$0.95 per lb C) $6.52 per lb D) $0.15 per lb 53) The following table shows the per-person carbon dioxide emissions for the United States

and for the rest of the world over six years. Non-U.S. 4.2 3.8 4 3 3.9 3.8

U.S. 18 17.5 17 18.6 17.5 16.5

The least-squares regression equation is y = 20.9878 - 0.9175x. If the non-U.S. emissions differ by 0.5 from one year to the next, by how much would you predict the U.S. emissions to differ? A) 0.46 B) -1.83 C) -0.92 D) -0.46

53)

54) Compute the least-squares regression line for the given data set.

x y

3 8.5

4 8.4

5 10

6 11.3

7 11.9

54)

8 13.1

A) y = 0.9400x + 8.5

B) y = 5.0648x + 0.9943

C) y = 0.9400x + 5.0648

D) y = 0.9943x + 5.0648

55) The following table presents the average price in dollars for a dozen eggs and a gallon of

55)

milk in several recent years. Dozen eggs 1.89 1.81 1.84 1.77 1.65 1.82 1.63 1.63

Gallon of milk 3.53 3.56 3.48 3.57 3.50 3.60 3.47 3.41

The least-squares regression equation is y = 2.8569 + 0.3750x. If the price of eggs differs by $0.25 from one year to the next, by how much would you expect the price of milk to differ? A) $0.38 B) $0.09 C) $1.50 D) -$0.09 56) One of the primary feeds for beef cattle is corn. The following table presents the average

price in dollars for a bushel of corn and a pound of ribeye steak for 10 consecutive months.

Construct a scatter plot of the price of ribeye (y) versus the price of corn (x). 29

56)

57) The following display from a graphing calculator presents the least-squares regression

57)

line for predicting the price of a certain commodity (y) from the price of a barrel of oil (x).

y = a+bx a = 5.04 b = 0.59 r2 = 0.57993 r = 0.76153

What is the correlation between the oil price and the commodity price? A) 0.76153 B) 0.57993 C) 0.59 D) 5.04 58) The following display from a graphing calculator presents the least-squares regression

line for predicting the price of a certain commodity (y) from the price of a barrel of oil (x).

y = a+bx a = 4.71 b = 0.49 r2 = 0.48909 r = 0.69935

Write the equation of the least-squares regression line. A) y = 0.49 + 0.48909x B) y = 0.49 + 4.71x y = 4.71 + 0.48909x C) D) y = 4.71 + 0.49x

58)

59) The following MINITAB output presents the least squares regression line for predicting

59)

the price of a certain commodity from the price of a barrel of oil. The regression equation is Commodity = -14.23741 + 1.991007 Oil Predictor Constant Oil

Coef -14.23741 1.991007

SE Coef 85.584316 0.82704

T -0.16635 2.407389

P 0.875949 0.073764

Write the equation of the least-squares regression line. A) y = 1.991007 - 14.23741x B) y = -14.23741 + 1.991007x C) y = -0.16635 + 2.407389x D) y = 0.875949 + 0.073764x 60) One of the primary feeds for beef cattle is corn. The following table presents the average

price in dollars for a bushel of corn and a pound of ribeye steak for 10 consecutive months. Corn Price ($/bu) 6.09 6.45 6.32 6.25 6.33 6.53

Ribeye Price ($/lb) 12.59 13.23 13.62 12.89 13.22 14.10

Compute the least-squares regression line for predicting the ribeye price from the corn price. A) y = 5.491 + 0.3372x B) y = -5.491 + 2.9654x C) y = -5.491 + 0.3372x D) y = 2.9654 - 5.491x

60)

61) The following table lists the heights in inches and weights in pounds of six football

61)

quarterbacks. Height 72 71 76 75 71 76

Weight 217 205 215 212 219 221

The least-squares regression equation is y = 158.7740 + 0.7627x. If two quarterbacks differ in height by 6 inches, by how much would you predict their weights to differ? A) 4.58 pounds B) 0.76 pounds C) 6.00 pounds D) 952.64 pounds 62) One of the primary feeds for beef cattle is corn. The following table presents the average

price in dollars for a bushel of corn and a pound of ribeye steak for 10 consecutive months. Corn Price ($/bu) 6.02 6.48 5.77 5.95 5.99 6.55

Ribeye Price ($/lb) 12.71 13.07 12.00 12.48 12.36 14.17

The least-squares regression line for predicting the ribeye price from the corn price is y = -0.7225 + 2.2069x. Predict the ribeye price in a month when the corn price was $6.28 per bushel. A) $13.14 per lb B) $14.52 per lb C) $12.48 per lb D) $13.86 per lb

62)

63) The following table presents the number of police officers (per 100,000 citizens) and the

63)

annual murder rate (per 100,000 citizens) for a sample of cities.

Compute the correlation coefficient between the per capita number of police officers and the per capita murder rate. A) -0.810 B) -0.808 C) -0.899 D) 0.808 64) For the following data set, compute the coefficient of determination.

x y

8 21

6 24

A) 0.728

3 20

2 33

10 27

64)

4 27

B) 0.074

C) 0.272

65) The total variation is the sum of the

and the

D) 0.926

65)

A) vertical difference, horizontal difference B) explained variation, unexplained variation C) explained difference, unexplained difference D) vertical variation, horizontal variation 66) Compute the least-squares regression line for predicting y from x given the following

66)

summary statistics: x = 7.4

sx = 2.9

sy = 8.6

r = 0.84

y = 47.1

A) y = 0.2833 + 28.6666x

B) y = 2.4910 + 28.6666x

C) y = 28.6666 + 0.2833x

D) y = 28.6666 + 2.4910x

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 67) When two variables are correlated, changing the value of one variable will cause a

change in value of the other variable.

67)

68) The closer r2 is to 0, the closer the predictions made by the least-squares regression line

68)

are to the actual values, on average. 69) The coefficient of determination may be interpreted as the proportion of variation in the

69)

outcome variable explained by the least-squares regression line. 70) A survey of U.S. adults showed that there is a negative correlation between age and

70)

education level. True or false: This means that people become less educated as they become older. 71) In a survey of cities in the United States,it is discovered that there is a positive

correlation between the number of police officers hired by the city and the number of crimes committed. True or false: Increasing the number of police officers causes the crime rate to increase.

71)

Answer Key Testname: C4

1) C 2) C 3) B 4) D 5) D 6) D 7) A 8) A 9) B 10) A 11) B 12) A 13) A 14) A 15) B 16) D 17) D 18) D 19) C 20) D 21) B 22) B 23) C 24) B 25) D 26) B 27) C 28) B 29) B 30) B 31) D 32) B 33) D 34) extrapolation 35) an influential point 36) residual 37) sum of squared residuals 38) A 39) A 40) B 41) D 42) A 43) C 44) B 45) D 46) B 47) A 48) A 49) C 36

Answer Key Testname: C4

50) B 51) B 52) D 53) D 54) D 55) B 56) D 57) A 58) D 59) B 60) B 61) A 62) A 63) C 64) B 65) B 66) D 67) FALSE 68) FALSE 69) TRUE 70) FALSE 71) FALSE

Exam Name___________________________________

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Charles has six songs on a playlist. Each song is by a different artist. The artists are

Drake, Post Malone, BTS, Ed Sheeran, Taylor Swift, and Cardi B. He programs his player to play the songs in a random order, without repetition. What is the probability that the first song is by Drake and the second song is by Cardi B? A) 0.0667 B) 0.0278 C) 0.0556 D) 0.0333 2) When ordering a certain type of computer, there are three choices of hard drive, five

choices for the amount of memory, four choices of video card, and three choices of monitor. In how many ways can a computer be ordered? A) 15 B) 36 C) 45 D) 180 3) In a certain city, 80% of high school students graduate. Of those who graduate, 30%

attend college. Find the probability that a randomly selected high school student will attend college. A) 0.5 B) 0.3 C) 0.24 D) 0.8 4) A quiz consists of four true–false questions and three multiple-choice questions with

four choices each. How many different sets of answers are there? A) 96 B) 80 C) 1024

D) 48

5) For the event described below, which of the following represents the complement of the

event? A sample of 442 software DVDs was selected. At least 29 of these were defective. A) Exactly 29 DVDs were not defective. B) Fewer than 29 DVDs were defective. C) At most 29 DVDs were defective. D) At most 413 DVDs were not defective. 6) Let A and B be events with P(A) = 0.3, P(B) = 0.9, and P(B A) = 0.2. Find P(A and B). A) 0.27

B) 0.06

C) 0.18

D) 0.5

7) Let A and B be events with P(A) = 0.5, P(B) = 0.7, and P(B A) = 0.7. Find P(A and B). A) 0.5

B) 0.35

C) 0.49

B) 0.05

C) 0.7

D) 0.7

8) Let A and B be events with P(A) = 0.1, P(B) = 0.5, and P(B A) = 0.6. Find P(A and B). A) 0.06

D) 0.3

9) For the event described below, which of the following represents the complement of the

event? A sample of 357 software DVDs was selected. Fewer than 44 of these were defective. A) More than 44 DVDs were not defective. B) Fewer than 44 DVDs were not defective. C) At most 44 DVDs were not defective. D) At least 44 DVDs were defective. 10) A penny and a nickel are tossed. Each is a fair coin, which means that heads and tails are

10)

equally likely. i. Construct a sample space containing equally likely outcomes. Each outcome should specify the results for both coins. ii . Find the probability that one coin comes up heads and the other comes up tails. A) i. {HH, HT, TH, TT} B) i. {HH, TH, TT} ii. 1/2 ii. 2/3 C) i. {HH, HT, TH, TT} D) i. {HH, TH, TT} ii. 1/4 ii. 1/3 11) Seven people, named Anna, Bob, Chandra, Darnell, Emma, Francisco, and Gina, will be

11)

interviewed for a job. The interviewer will choose two at random to interview on the first day. What is the probability that Anna is interviewed first and Darnell is interviewed second? A) 0.0408 B) 0.0204 C) 0.0238 D) 0.0278 12) For the event described below, which of the following represents the complement of the

12)

event? A sample of 491 software DVDs was selected. Exactly 42 of these were defective. A) Exactly 42 DVDs were not defective. B) The number of defective DVDs was not equal to 42. C) No more than 42 DVDs were defective. D) Exactly 449 DVDs were not defective. 13) A local pizza parlor is offering a half-price deal on any pizza with one topping. There are

13)

twelve toppings from which to choose. In addition, there are four different choices for the size of the pizza, and three choices for the type of crust.In how many ways can a pizza be ordered? A) 144 B) 19 C) 72 D) 288 14) If P(A) = 0.69, P(B) = 0.4, and P(A or B) = 0.73, are A and B mutually exclusive? A) No

B) Yes

14)

15) Nanette must pass through three doors as she walks from her company's foyer to her

15)

office. Each of these doors may be locked or unlocked. Let B be the event that exactly two doors are in the same condition. List the outcomes of B. [Let "L" designate "locked" and "U" designate "unlocked".] A) {LLL, LLU, LUL, LUU, ULL, ULU, UUL, UUU} B) {LLU, LUL, ULL} C) {LLU, LUL, ULL, LUU, ULU, UUL} D) None of these. 16) There are 29,091 undergraduate students enrolled at a certain university. The age

16)

distribution is as follows: Age Range Number 13 - 14 4 15 - 17 207 18 - 22 11,042 23 - 30 10,965 31 and up 6873 Total 29,091 What is the probability that a student is less than 18 years old? A) 0.00014 B) 0.0073 C) 0.0071

D) 0.236

17) According to a survey, 52% of teenagers could recognize a picture of legendary film star

17)

John Wayne. What is the probability that a randomly-selected teenager could recognize John Wayne? A) 0.92 B) 0.48 C) 0.01 D) 0.52 18) On a TV game show, a contestant is shown 11 products from a grocery store and is asked

18)

to choose the three least-expensive items in the set. The three chosen items need not be in any particular order. In how many ways can the contestant choose the three items? A) 990 B) 6,652,800 C) 6 D) 165 19) A section of an exam contains two multiple-choice questions, each with three answer

19)

choices (listed "A", "B", and "C"). Assuming the outcomes to be equally likely, find the probability (as a reduced fraction) that both answers are the same ("AA", "BB" or "CC"). [Hint: List all the outcomes of the sample space first.] A) 1/9 B) 1/3 C) 1/6 D) 1/27 20) If P(AC ) = 0.41, find P(A). A) 0.41

20)

B) 0.205

C) 0.59

D) 0.295

21) A section of an exam contains two multiple-choice questions, each with three answer

21)

choices (listed "A", "B", and "C"). Assuming the outcomes to be equally likely, find the probability (as a reduced fraction) that the second answer is either "B" or "C". [Hint: List all the outcomes of the sample space first.] A) 5/9 B) 7/9 C) 2/3 D) 1/3 22) The letters "A", "B", "C", "D", "E", and "F" are written on six slips of paper, and the

22)

slips are placed into a hat. If the slips are drawn randomly without replacement, what is the probability that "E" is drawn first and "F" is drawn second? A) 0.024 B) 0.028 C) 0.033 D) 0.039 23) Assume a soldier is selected at random from the Army. Determine whether the events A

23)

and B are independent, mutually exclusive, or neither. A: The soldier is a colonel. B: The soldier is a lieutenant. A) neither B) mutually exclusive

C) independent

24) Out of 920 items checked out of a public library, 397 were fiction books, 285 were

24)

non-fiction books, and 238 were videos (of any genre). What is the probability that a randomly-selected item was not a video? A) 0.259 B) 0.432 C) 0.741 D) 0.349 25) A poll was taken of 14,360 working adults aged 40-70 to determine their level of

education. The participants were classified by sex and by level of education. The results were as follows. Education Level High School or Less Bachelor's Degree Master's Degree Ph.D. Total

Male 3092 3607 584 50 7333

Female 2294 4247 437 49 7027

Total 5386 7854 1021 99 14,360

A person is selected at random. Compute the probability that the person is male or has a Ph.D. A) 0.511 B) 0.007 C) 0.518 D) 0.514

25)

26) On a certain day, a cheese packaging facility packaged 500 units of mozzarella cheese.

26)

Some of these packages had major flaws, some had minor flaws, and some had both major and minor flaws. The following table presents the results. Minor Flaw No Minor Flaw Major Flaw 24 31 No Major Flaw 53 392 Find the probability that randomly chosen cheese package has a flaw (major or minor). A) 0.216 B) 0.168 C) 0.784 D) 0.264 27) What is the correct relationship between events A and B?

27)

A: Kathleen made an A on her Biology final exam. B: Kathleen did not make an A on the Biology final exam. A) A and B are mutually exclusive.

B) A and B are complementary.

C) A and B are not mutually exclusive.

D) If B is untrue, A is untrue.

28) In a recent semester at a local university, 490 students enrolled in both General

28)

Chemistry and Calculus I. Of these students, 66 received an A in general chemistry, 58 received an A in calculus, and 30 received an A in both general chemistry and calculus. Find the probability that a randomly chosen student received an A in general chemistry or calculus or both. A) 0.758 B) 0.253 C) 0.192 D) 0.314 29) The arrow on the spinner shown below can be spun so that the arrowhead eventually

stops in one of the three sectors labeled "A", "B", or "C". The spinner is spun 109 times and comes up "A" 56 times. Use the Empirical Rule to approximate the probability that the spinner comes up "A".

A) 0.5

B) 0.514

C) 0.486

D) 0.339

29)

30) Nanette must pass through three doors as she walks from her company's foyer to her

30)

office. Each of these doors may be locked or unlocked. Let C be the event that at least two doors are in the same condition. List the outcomes of C. [Let "L" designate "locked" and "U" designate "unlocked".] A) {LLL, LLU, LUL, LUU, ULL, ULU, UUL, UUU} B) {LLL, UUU, LLU, LUL, ULL} C) {LLU, LUL, ULL, LUU, ULU, UUL} D) None of these. 31) What is the correct relationship between events A and B?

31)

A: Laura participated in an out-of-town volleyball game at 11:00 AM last Friday. B: Laura met with her academic advisor on campus at 11:00 AM last Friday. A) A and B are mutually exclusive.

B) A and B are complementary.

C) A and B are not mutually exclusive.

D) If B is true, A is true.

32) Evaluate the factorial: 6! A) 720

32) B) 36

C) 30

D) 120

33) Let E be the event that a corn crop has an infestation of ear worms, and let B be the event

33)

that a corn crop has an infestation of corn borers. Suppose that P(E) = 0.27, P(B) = 0.11, and P(E and B) = 0.1. Find the probability that a corn crop has no corn borer infestation. A) 0.73 B) 0.62 C) 0.28 D) 0.89 34) A fast-food restaurant chain has 622 outlets in the United States. The following table

categorizes them by city population and location and presents the number of outlets in each category. An outlet is chosen at random from the 622 to test market a new menu. Region Population of city Under 50,000 50,000 - 500,000 Over 500,000

NE 29 55 75

SE 32 44 124

SW NW 34 17 51 35 77 49

Given that the outlet is located in the West (either SW or NW), what is the probability that it is in a city with population 50,000–500,000? A) 0.327 B) 0.138 C) 0.238 D) 0.703

34)

35) A 12-sided die can be made from a geometric solid called a

35)

dodecahedron. Assume that a fair dodecahedron is rolled. The sample space is {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12}. Find P(10). A) 5/6

B) 1/6

C) 1/12

D) 3/4

36) A geneticist is studying two genes. Each gene can be either dominant or recessive. A

36)

sample of 100 individuals is categorized as follows.

Gene 1 Dominant Gene 1 Recessive

Gene 2 Dominant 14 21

Gene 2 Recessive 26 39

Given that gene 1 is dominant, what is the probability that gene 2 is dominant? A) 0.40 B) 2.50 C) 0.35 D) 0.39 37) On a TV game show, a contestant is shown 9 products from a grocery store and is asked

37)

to choose the three least-expensive items in the set, and then correctly arrange these three items in order of price. In how many ways can the contestant choose the three items? A) 84 B) 60,480 C) 504 D) 6 38) A fair die is rolled five times. What is the probability that it comes up 1 at least once? A) 0.5981

B) 0.5177

C) 0.8333

D) 0.1667

39) Nanette must pass through three doors as she walks from her company's foyer to her

office. Each of these doors may be locked or unlocked. Let B be the event that exactly two doors are locked. List the outcomes of B. [Let "L" designate "locked" and "U" designate "unlocked".] A) {LLU, LUL, ULL, LUU, ULU, UUL} B) {LLU, LUL, ULL} C) {LLL, LLU, LUL, LUU, ULL, ULU, UUL, UUU} D) None of these.

38)

39)

40) On a recent Saturday, a total of 1087 people visited a local library. Of these people, 249

40)

were under age 10, 479 were aged 10–18, 180 were aged 19–30, and the rest were more than 30 years old. One person is sampled at random. What is the probability that the person is less than 19 years old? A) 0.728 B) 0.441 C) 0.67 D) 0.229 41) There are 25 students in a sixth-grade class. On a cold winter day in February, many of

41)

the students had runny noses and sore throats. After examining each student, the school nurse constructed the following table:

Runny nose No runny nose

Sore throat No sore throat 3 2 6 14

Find the probability that a randomly-selected student has a sore throat. A) 0.20 B) 0.24 C) 0.36 D) 0.50 42) A survey asked 33,691 homeowners how many pets they owned. The results were as

42)

follows: Number of Pets 0 1 2 3 4 or more Total

Number of Homeowners 5502 10,243 10,328 6971 647 33,691

What is the probability that a sampled homeowner has three pets? A) 0.774 B) 0.207 C) 0.019

D) 0.226

43) Let E be the event that a corn crop has an infestation of ear worms, and let B be the event

43)

that a corn crop has an infestation of corn borers. Suppose that P(E) = 0.24, P(B) = 0.17, and P(E and B) = 0.1. Find the probability that a corn crop has either an ear worm infestation, a corn borer infestation, or both. A) 0.1 B) 0.31 C) 0.59 D) 0.51 44) If P(A) = 0.54, P(B) = 0.57, and P(A and B) = 0.29, find P(A or B). A) 0.145

B) 0.82

C) 0.555

44) D) 0.29

45) At the campus cafeteria, a diner can purchase a "meal deal" that consists of an entree, a

45)

side dish, and a dessert. There are 4 choices for the entree, 6 choices for the side dish, and 6 choices for dessert. How many different meal deals are possible? A) 84 B) 560 C) 144 D) 16 46) A Karate club consists of 54 persons holding a black belt (highest rating), 64 persons

46)

holding a brown belt (middle rating), and 79 persons holding a purple belt (lowest rating). What is the probability that a randomly-selected club member holds a black belt? A) 0.378 B) 0.622 C) 0.274 D) 0.726 47) For this year's mayoral election, voter dissatisfaction is very high. In a survey of 700

47)

likely voters, 182 said they planned to write in an independent candidate rather than vote for the Democrat or Republican candidate for mayor. Estimate the percentage of voters who plan to write in an independent candidate? A) 18.2% B) 70% C) 26% D) 74% 48) Let A and B be events with P(A) = 0.8, P(B) = 0.4, and P(B|A) = 0.2. Find P(A and B). A) 0.25

B) 0.32

C) 0.16

48)

D) 0.08

49) A 12-sided die can be made from a geometric solid called a

49)

dodecahedron. Assume that a fair dodecahedron is rolled. The sample space is {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12}. Find P(Greater than 8). A) 1/12

B) 1/4

C) 1/3

D) 7/12

50) A survey asked 33,625 homeowners how many pets they owned. The results were as

follows: Number of Pets 0 1 2 3 4 or more Total

Number of Homeowners 5617 10,676 10,435 5920 977 33,625

Assume this is a simple random sample of homeowners. Use the Empirical Method to estimate the probability that a homeowner has at least one pet. A) 0.167 B) 0.799 C) 0.833 D) 0.201 9

50)

51) The probability that a certain make of car will need repairs in the first six months is 0.2.

51)

A dealer sells four such cars. What is the probability that at least one of them will require repairs in the first six months? A) 0.0016 B) 0.9984 C) 0.5904 D) 0.4096 52) For this year's mayoral election, voter dissatisfaction is very high. In a survey of 500

52)

likely voters, 210 said they planned to write in an independent candidate rather than vote for the Democrat or Republican candidate for mayor. What is the probability that a surveyed voter plans to write in an independent candidate? A) 0.58 B) 0.42 C) 0.5 D) 0.21 53) A survey asked 31,156 homeowners how many pets they owned. The results were as

53)

follows: Number of Pets 0 1 2 3 4 or more Total

Number of Homeowners 6700 9650 8318 5567 921 31,156

What is the probability that a sampled homeowner has more than 1 pet? A) 0.215 B) 0.475 C) 0.525 D) 0.208 54) In a recent semester at a local university, 540 students enrolled in both General

Chemistry and Calculus I. Of these students, 51 received an A in general chemistry, 59 received an A in calculus, and 30 received an A in both general chemistry and calculus. Find the probability that a randomly chosen student did not receive an A in general chemistry. A) 0.85 B) 0.094 C) 0.906 D) 0.891

54)

55) On a certain day, a cheese packaging facility packaged 560 units of mozzarella cheese.

55)

Some of these packages had major flaws, some had minor flaws, and some had both major and minor flaws. The following table presents the results. Minor Flaw No Minor Flaw Major Flaw 16 25 No Major Flaw 54 465 Find the probability that randomly chosen cheese package has a major flaw. A) 0.073 B) 0.045 C) 0.029 D) 0.088 56) A fair coin is tossed four times. What is the probability that the sequence of tosses is

THHT? A) 0.25

B) 0.038

C) 0.0625

56)

D) 0.125

57) A lot of 1000 components contains 300 that are defective. Two components are drawn at

57)

random and tested. Let A be the event that the first component drawn is defective, and let B be the event that the second component drawn is defective. Find P(B|A). A) 0.3

B) 0.0033

C) 0.0898

D) 0.2993

58) A poll was taken of 13,795 working adults aged 40-70 to determine their level of

58)

education. The participants were classified by sex and by level of education. The results were as follows. Education Level High School or Less Bachelor's Degree Master's Degree Ph.D. Total

Male 3449 3141 564 54 7208

Female 2235 3855 437 60 6587

Total 5684 6996 1001 114 13,795

A person is selected at random. Compute the probability that the person has a master's degree. A) 0.036 B) 0.073 C) 0.041 D) 0.032 59) What is the correct relationship between events A and B?

A: Karl is college graduate. B: Karl is a high school graduate. A) A and B are mutually exclusive.

B) B is the complement of A.

C) A and B are not mutually exclusive.

D) If B is not true, A cannot be true. 11

59)

60) The numbers 1 through 7 are written in separate slips of paper, and the slips are placed

60)

into a box. Then, 4 of these slips are drawn at random. What is the probability that the drawn slips are "1", "2", "3", and "4", in that order? A) 0.68568 B) 0.02857 C) 0.00119 D) 0.02856 61) A lot of 1000 components contains 200 that are defective. Two components are drawn at

61)

random and tested. Let A be the event that the first component drawn is defective, and let B be the event that the second component drawn is defective. Find P(A). A) 0.0398

B) 0.005

C) 0.1992

D) 0.2

62) A committee consists of 10 women and 7 men. Three members are chosen as officers.

What is the probability that all three officers are women? A) 0.03392 B) 0.1765 C) 0.2035

62)

D) 0.0515

63) A geneticist is studying two genes. Each gene can be either dominant or recessive. A

63)

sample of 100 individuals is categorized as follows.

Gene 1 Dominant Gene 1 Recessive

Gene 2 Dominant 12 28

Gene 2 Recessive 18 42

What is the probability that in a randomly-sampled individual, gene 2 is dominant? A) 0.40 B) 0.70 C) 0.60 D) 0.12 64) There are 25 students in a sixth-grade class. On a cold winter day in February, many of

the students had runny noses and sore throats. After examining each student, the school nurse constructed the following table:

Runny nose No runny nose

Sore throat No sore throat 5 5 3 12

Find the probability that a randomly-selected student has neither a runny nose nor a sore throat. A) 0.80 B) 0.32 C) 0.20 D) 0.48

64)

65) In a poll of 628 university students, 276 said that they were opposed to legalizing

65)

marijuana. What is the probability that a surveyed student opposes legalization of marijuana? A) 0.561 B) 0.216 C) 0.439 D) 0.784 66) Let A and B be events with P(A) = 0.5, P(B) = 0.6, and P(A and B) = 0.05. Are A and B

independent? A) No

66)

B) Yes

67) There are 20 students in a sixth-grade class. On a cold winter day in February, many of

67)

the students had runny noses and sore throats. After examining each student, the school nurse constructed the following table:

Runny nose No runny nose

Sore throat No sore throat 5 2 4 9

Find the probability that a randomly-selected student has a runny nose or a sore throat. A) 0.25 B) 0.30 C) 0.80 D) 0.55 68) A fast-food restaurant chain has 628 outlets in the United States. The following table

68)

categorizes them by city population and location and presents the number of outlets in each category. An outlet is chosen at random from the 628 to test market a new menu. Region Population of city Under 50,000 50,000 - 500,000 Over 500,000

NE 26 51 80

SE 35 50 124

SW NW 33 15 52 45 76 41

Given that the outlet is located in a city with a population under 50,000, what is the probability that it is in the Southwest? A) 0.174 B) 0.053 C) 0.303 D) 0.321 69) A coin is tossed 764 times and comes up heads 397 times. Use the Empirical Method to

approximate the probability that the coin comes up heads. A) 0.342 B) 0.5 C) 0.52

D) 0.48

69)

70) A lot of 10 components contains 3 that are defective. Two components are drawn at

70)

random and tested. Let A be the event that that the first component drawn is defective, and B be the event that the second component drawn is defective. a. Find P(A). b. Find P(B|A). c. Find P(A and B). d. Are A and B independent? A) a. 0.3333 B) a. 0.3000 b. 0.1250 b. 0.3333 c. 0.1000 c. 0.1000 d. Yes d. No

C) a. 0.3000

D) a. 0.3000

b. 0.2222 c. 0.0667 d. Yes

b. 0.2222 c. 0.0667 d. No

71) A fair die is rolled two times. What is the probability that both rolls are 3? A) 0.028

B) 0.167

C) 0.083

71)

D) 0.0046

72) A section of an exam contains two multiple-choice questions, each with three answer

72)

choices (listed "A", "B", and "C"). Assuming the outcomes to be equally likely, find the probability (as a reduced fraction) that at least one answer is "A". [Hint: List all the outcomes of the sample space first.] A) 1/3 B) 5/9 C) 2/3 D) 7/9 73) A study suggests that 14.7% of all four-digit personal identification numbers, or PIN

73)

codes, have a repeating-digits format such as 2525. Assuming this to be true, if the PIN codes of four people are selected at random, what is the probability that at least one of them will have repeating digits? A) 0.5880 B) 0.5294 C) 0.4706 D) 0.4120 74) A survey asked respondents to indicate their level of satisfaction with government

spending. The results are show below. Response Very satisfied Somewhat satisfied Dissatisfied Total

Number 924 4921 4036 9881

What is the probability that a sampled person was only somewhat satisfied or dissatisfied with government's spending? A) 0.897 B) 0.103 C) 0.906 D) 0.094

74)

75) There are 25 students in a sixth-grade class. On a cold winter day in February, many of

75)

the students had runny noses and sore throats. After examining each student, the school nurse constructed the following table:

Runny nose No runny nose

Sore throat No sore throat 5 4 6 10

Find the probability that a randomly-selected student has a runny nose. A) 0.64 B) 1.25 C) 0.20 D) 0.36 76) Evaluate the permutation: 11P 6 A) 66

76)

B) 332,640

C) 39,916,800

D) 462

77) A Karate club consists of 52 persons holding a black belt (highest rating), 69 persons

77)

holding a brown belt (middle rating), and 77 persons holding a purple belt (lowest rating). What is the probability that a randomly-selected club member holds a brown belt or a purple belt? A) 0.644 B) 0.356 C) 0.737 D) 0.263 78) If P(A) = 0.33, find P(A C). A) 0.67

78)

B) 0.33

C) 0.165

D) 0.335

79) A survey asked respondents to indicate their level of satisfaction with government

spending. The results are show below. Response Very satisfied Somewhat satisfied Dissatisfied Total

Number 601 3821 5309 9731

Assume this is a simple random sample from a population. Use the Empirical Method to estimate the probability that a person is dissatisfied with government's spending? A) 0.33 B) 0.454 C) 0.546 D) 0.581

79)

80) On a certain day, a cheese packaging facility packaged 500 units of mozzarella cheese.

80)

Some of these packages had major flaws, some had minor flaws, and some had both major andminor flaws. The following table presents the results. Minor Flaw No Minor Flaw Major Flaw 16 36 No Major Flaw 73 375 Find the probability that randomly chosen cheese package has a minor flaw. A) 0.237 B) 0.178 C) 0.104 D) 0.146 81) Nanette must pass through three doors as she walks from her company's foyer to her

81)

office. Each of these doors may be locked or unlocked. List the outcomes of the sample space. A) {LLL, UUU} B) {LLU, LUL, ULL, UUL, ULL, LUU} C) {LLL, LLU, LUL, LUU, ULL, ULU, UUL, UUU} D) None of these. 82) A section of an exam contains two multiple-choice questions, each with three answer

82)

choices (listed "A", "B", and "C"). Assuming the outcomes to be equally likely, find the probability (as a reduced fraction) that both answers are "C". [Hint: List all the outcomes of the sample space first.] A) 1/27 B) 1/9 C) 1/3 D) 1/6 83) A lot of 1000 components contains 150 that are defective. Two components are drawn at

83)

random and tested. Let A be the event that the first component drawn is defective, and let B be the event that the second component drawn is defective. Find P(B and A). A) 0.0224

B) 0.0067

C) 0.1491

D) 0.15

84) A section of an exam contains two multiple-choice questions, each with three answer

84)

choices (listed "A", "B", and "C"). Assuming the outcomes to be equally likely, find the probability (as a reduced fraction) that neither of the answers is "B". [Hint: List all the outcomes of the sample space first.] A) 2/3 B) 5/9 C) 4/9 D) 1/3 85) Let A and B be events with P(A) = 0.3, P(B) = 0.2, and P(A and B) = 0.06. Are A and B

independent? A) No

B) Yes

85)

86) Let A and B be events with P(A) = 0.9, P(B) = 0.6, and P(A and B) = 0.27. Are A and B

mutually exclusive? A) No

B) Yes

87) Let A, B and C be independent events with P(A) = 0.4, P(B) = 0.1, and P(C) = 0.3. Find

P(A and B and C). A) 0.133

86)

B) 0.04

C) 0.015

87)

D) 0.012

88) William and Mary are going bowling. The probability that Mary scores more than 175 is

88)

0.5, and the probability that William scores more than 175 is 0.7. Their scores are independent. a. Find the probability that both score more than 175. b. Given that William scores more than 175, the probability that Mary scores higher than William is 0.1. Find the probability that William scores more than 175 and Mary scores higher than William. A) a. 0.35 B) a. 0.35 C) a. 0.25 D) a. 0.25 b. 0.07 b. 0.05 b. 0.07 b. 0.05 89) A section of an exam contains two multiple-choice questions, each with three answer

89)

choices (listed "A", "B", and "C"). List all the outcomes of the sample space. A) {AB, AC, BA, BC, CA, CB} B) {AA, AB, AC, BB, BC, CC} C) {AA, AB, AC, BA, BB, BC, CA, CB, CC} D) {A, B, C} 90) Nanette must pass through three doors as she walks from her company's foyer to her

90)

office. Each of these doors may be locked or unlocked. Let A be the event that all three doors are in the same condition. List the outcomes of A. [Let "L" designate "locked" and "U" designate "unlocked".] A) {LLL, UUU} B) {LLL} C) {LLL, LLU, LUL, LUU, ULL, ULU, UUL, UUU} D) None of these. 91) Every day, Bill buys a lottery ticket. Each ticket has probability 0.25 of winning a prize.

After seven days, what is the probability that Bill has won at least one prize? A) 0.0001 B) 0.9999 C) 0.1335 D) 0.8665

91)

92) So far this season, the university's football team has executed 151 running plays, 152

92)

passing plays, and 18 "trick" plays. What is the probability that the team will not execute a trick play? A) 0.944 B) 0.059 C) 0.056 D) 0.941 93) On a certain day, a cheese packaging facility packaged 480 units of mozzarella cheese.

93)

Some of these packages had major flaws, some had minor flaws, and some had both major and minor flaws. The following table presents the results. Minor Flaw No Minor Flaw Major Flaw 15 28 No Major Flaw 53 384 Find the probability that randomly chosen cheese package has no major flaw. A) 0.91 B) 0.8 C) 0.831 D) 0.2 94) In the game of tic-tac-toe, if all moves are performed randomly the probability that the

94)

game will end in a draw is 0.127. Suppose 12 random games of tic-tac-toe are played. What is the probability that at least one of them will end in a draw? A) 0.0001 B) 0.5000 C) 0.8040 D) 0.0531 95) Nanette must pass through three doors as she walks from her company's foyer to her

95)

office. Each of these doors may be locked or unlocked. Let C be the event that at least two doors are unlocked. List the outcomes of C. [Let "L" designate "locked" and "U" designate "unlocked".] A) {LLU, LUL, ULL, LUU, ULU, UUL} B) {UUU, LUU, ULU, UUL} C) {LLL, LLU, LUL, LUU, ULL, ULU, UUL, UUU} D) None of these. 96) In a poll of 420 university students, 197 said that they were opposed to legalizing

96)

marijuana. Estimate the percentage of students who oppose legalizing marijuana. A) 46.9% B) 11.7% C) 53.1% D) 88.3% 97) An unfair coin has a probability 0.4 of landing heads. The coin is tossed four times. What

is the probability that it lands heads at least once? A) 0.936 B) 0.8704 C) 0.25

D) 0.9744

98) If P(A) = 0.43, P(B) = 0.21, and P(A or B) = 0.64, are A and B mutually exclusive? A) No

B) Yes

97)

98)

99) Evaluate the combination: 11C 7 A) 39,916,800

99)

B) 77

C) 1,663,200

D) 330

100) A geneticist is studying two genes. Each gene can be either dominant or recessive. A

100)

sample of 100 individuals is categorized as follows.

Gene 1 Dominant Gene 1 Recessive

Gene 2 Dominant 18 27

Gene 2 Recessive 22 33

Two genes are said to be in linkage equilibrium if the event that gene 1 is dominant is independent of the event that gene 2 is dominant. Are these genes in linkage equilibrium? A) No B) Yes 101) There are 30,136 undergraduate students enrolled at a certain university. The age

101)

distribution is as follows: Age Range Number 13 - 14 3 15 - 17 34 18 - 22 12,467 23 - 30 11,101 31 and up 6531 Total 30,136 What is the probability that a student is between 23 and 30 years old? A) 0.368 B) 0.415 C) 0.585 D) 0.217 102) Let A and B be events with P(A) = 0.4, P(B) = 0.8. Assume that A and B are independent.

Find P(A and B). A) 0.4

B) 0.32

C) 0.5

102)

D) 0.8

103) So far this season, the university's football team has executed 146 running plays, 167

103)

passing plays, and 22 "trick" plays. What is the probability that the team will execute a passing play? A) 0.436 B) 0.501 C) 0.534 D) 0.499 104) If P(A) = 0.57, P(B) = 0.35, and A and B are mutually exclusive, find P(A or B). A) 0.92

B) 0.46

C) 0.22

D) 0

104)

105) A geneticist is studying two genes. Each gene can be either dominant or recessive. A

105)

sample of 100 individuals is categorized as follows.

Gene 1 Dominant Gene 1 Recessive

Gene 2 Dominant 4 36

Gene 2 Recessive 6 54

What is the probability that in a randomly-sampled individual, gene 1 is dominant? A) 0.90 B) 0.40 C) 0.10 D) 0.04 106) On a recent Saturday, a total of 1049 people visited a local library. Of these people, 245

106)

were under age 10, 464 were aged 10–18, 181 were aged 19–30, and the rest were more than 30 years old. One person is sampled at random. What is the probability that the person is more than 30 years old? A) 0.709 B) 0.152 C) 0.676 D) 0.324 107) A poll was taken of 14,537 working adults aged 40-70 to determine their level of

107)

education. The participants were classified by sex and by level of education. The results were as follows. Education Level High School or Less Bachelor's Degree Master's Degree Ph.D. Total

Male 3199 3872 595 71 7737

Female 2729 3538 482 51 6800

Total 5928 7410 1077 122 14,537

A person is selected at random. Compute the probability that the person is female and has a bachelor's degree. A) 0.266 B) 0.243 C) 0.520 D) 0.978 108) A 12-sided die can be made from a geometric solid called a

108)

dodecahedron. Assume that a fair dodecahedron is rolled. The sample space is {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12}. Find P(Less than 4). A) 1/4

B) 1/12

C) 1/3

D) 7/12

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 109) The Empirical Method can be used to calculate the exact probability of an event.

109)

ESSAY. Write your answer in the space provided or on a separate sheet of paper. 110) A computer password consists of nine characters. Replications are allowed.

a. How many different passwords are possible if each character may be any lowercase letter or digit? b. How many different passwords are possible if each character may be any lowercase letter? c. How many different passwords are possible if each character may be any lowercase letter or digit, and at least one character must be a digit? d. A computer is generating passwords at random, and each character is equally likely to be any of the 26 lowercase letters or 10 digits. Replications are allowed. What is the probability that the password will contain all letters? e. A computer system requires the password to contain at least one digit. If nine characters are generated at random from the 26 lowercase letters and 10 digits, what is the probability that they will form a valid password? 111) Human genetic material (DNA) is made up of sequences of the molecules adenosine (A), guanine (G),

cytosine (C), and thymine (T), which are called bases. A codon is a sequence of three bases. Replicates are allowed, so AAA, CGC, and so forth are codons. Codons are important because each codon causes a different amino acid to be included in a protein. a. How many different codons are there? b. How many different codons are there in which all three bases are different? c. The bases A and G are called purines, while C and T are called pyrimidines. How many different codons are there in which the third base is a purine and the others are pyrimidines? d. What is the probability that all three bases are different? e. What is the probability that the third base is a purine and the others are pyrimidines?

Answer Key Testname: C5

1) D 2) D 3) C 4) C 5) B 6) B 7) B 8) A 9) D 10) A 11) C 12) B 13) A 14) A 15) C 16) B 17) D 18) D 19) B 20) C 21) C 22) C 23) B 24) C 25) D 26) A 27) B 28) C 29) B 30) A 31) A 32) A 33) D 34) A 35) C 36) C 37) C 38) A 39) B 40) C 41) C 42) B 43) B 44) B 45) C 46) C 47) C 48) C 49) C 50) C 22

Answer Key Testname: C5

51) C 52) B 53) B 54) C 55) A 56) C 57) D 58) B 59) C 60) C 61) D 62) B 63) A 64) D 65) C 66) A 67) D 68) C 69) C 70) D 71) A 72) B 73) C 74) C 75) D 76) B 77) C 78) A 79) C 80) B 81) C 82) B 83) A 84) C 85) B 86) A 87) D 88) A 89) C 90) A 91) D 92) A 93) A 94) C 95) B 96) A 97) B 98) B 99) D 100) B 23

Answer Key Testname: C5

101) A 102) B 103) D 104) A 105) C 106) B 107) B 108) A 109) FALSE 110) a. 369

b. 269 c. 369 - 269 d. 0.0535 e. 0.9465 111) a. 64 b. 24 c. 8 d. 0.375 e. 0.125

Exam Name___________________________________

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Following is a probability histogram for the number of children a woman has. The

numbers on the tops of the rectangles are the heights.

What is the probability that a randomly chosen woman has either four or five children? A) 0.121 B) 0.239 C) 0.149 D) 0.002

2) Following is a probability histogram for the number of children a woman has. The

numbers on the tops of the rectangles are the heights.

What is the probability that a randomly chosen woman has exactly two children? A) 0.404 B) 0.244 C) 0.160 D) 0.433 3) In a recent Pew poll, 11% of adults said that they consider themselves to be "gamers."

Assume that 14 adults are randomly sampled. Use the binomial probability distribution to compute the probability that exactly three of them consider themselves to be gamers. A) 0.866 B) 0.001 C) 0.068 D) 0.134 4) There are 5000 undergraduates registered at a certain college. Of them, 478 are taking

one course, 645 are taking two courses, 568 are taking three courses, 1357 are taking five courses, and 88 are taking six courses. Let X be the number of courses taken by a student randomly sampled from this population. Find the probability distribution of X. x 1 2 3 4 5 6 A) P(x) 0.0972 0.1296 0.1128 0.3736 0.2702 0.0166 x 1 2 3 4 5 6 B) P(x) 0.0956 0.1296 0.1136 0.3736 0.2714 0.0162 x 1 2 3 4 5 6 C) P(x) 0.0956 0.1290 0.1136 0.3728 0.2714 0.0176 x 1 2 3 4 5 6 D) P(x) 0.0972 0.1290 0.1128 0.3728 0.2702 0.0180

5) In a recent Pew poll, 40% of adults said that they play video games. Assume that 8 adults

are randomly sampled. Use the binomial probability distribution to compute the probability that exactly four of them play video games. A) 0.232 B) 0.129 C) 0.768 D) 0.026 6) Following is a probability histogram for the number of children a woman has. The

numbers on the tops of the rectangles are the heights.

What is the probability that a randomly chosen woman has fewer than two children? A) 0.160 B) 0.433 C) 0.677 D) 0.244 7) The General Social Survey asked 827 people how many days they would wait to seek

medical treatment if they were suffering pain that interfered with their ability to work. The results are presented in the following table. Number of Days 0 1 2 3 4 5 Total

Frequency 27 436 263 72 19 10 827

Consider these 827 people to be a population. Let X be the number of days for a person sampled at random from this population. 3

i. Construct the probability distribution of X. ii. Find the probability that a person would wait for 3 days. iii. Find the probability that a person would wait more than 2 days. A) i. B) i. x P(x) x P(x) 0.0326 0.0326 0 0 0.5272 0.5272 1 1 0.2999 0.3180 2 2 0.1052 0.0871 3 3 0.0230 0.0230 4 4 0.0121 0.0121 5 5 ii. 0.860 iii. 0.440 C) i. x 0 1 2 3 4 5

ii. 0.087 iii. 0.122 D) i. x 0 1 2 3 4 5

P(x) 0.0326 0.5272 0.2999 0.1052 0.0230 0.0121

ii. 0.105 iii. 0.140

P(x) 0.0326 0.5272 0.3180 0.0871 0.0230 0.0121

ii. 0.878 iii. 0.440

8) It is estimated that 40% of households own a riding lawn mower. A sample of 13

households is studied. What is the probability that more than 10 of these own a riding lawn mower? A) 0.9922 B) 0.0013 C) 0.0001 D) 0.0078 9) The number of customers in a line at a supermarket express checkout counter is a

random variable with the following probability distribution. x P(x)

0 0.10

1 0.25

Compute the mean x. A) 0.43

2 0.30

3 0.18

4 0.07

5 0.10

B) 2.17

C) 0.36

D) 0.17

10) Determine whether the random variable described is discrete or continuous.

10)

The number of 3-point shots made in a basketball game A) discrete B) continuous 11) In a poll conducted by a survey firm, 84% of respondents said that their jobs were

11)

sometimes or always stressful. Ten workers are chosen at random. What is the probability that exactly 6 of them find their jobs stressful? A) 0.9517 B) 0.0018 C) 0.0012 D) 0.0483 12) Determine whether the random variable described is discrete or continuous.

12)

The number of minutes you must wait in line at the grocery store A) continuous B) discrete 13) The number of typographical errors in a document follows a Poisson distribution with a

13)

mean of 4 errors per page. Let X represent the number of errors on 2 pages. Find x. A) 2.8 B) 8 C) 4 D) 9 14) A student takes a true-false test that has 13 questions and guesses randomly at each

14)

answer. Let X be the number of questions answered correctly. Find P(Fewer than 4) A) 0.8666 B) 0.0112 C) 0.1334 D) 0.0461 15) Last year, a manufacturer produced 350,000 DVD players. Of these, approximately 1%

15)

were defective. Assume that a simple random sample of n = 140 players is drawn. Use the Poisson approximation to the binomial distribution to compute the standard deviation of the number of DVD players that were defective. A) 48.3 B) 1.4 C) 1.2 D) 1 16) The number of typographical errors in a document follows a Poisson distribution with a

16)

mean of 2 errors per page. Let X represent the number of errors on 3 pages. Find P(Less than 3). A) 0.0174 B) 0.6767 C) 0.0620 D) 0.0595 17) An environmental scientist obtains a sample of water from an irrigation canal that

contains a certain type of bacteria at a concentration of 6 per milliliter. Find the mean number of bacteria in a 8-milliliter sample. A) 48 B) 6 C) 2.4 D) 6.9

17)

18) In the game of craps, two dice are rolled, and people bet on the outcome. For example,

you can bet $1 that the dice will total 11. The probability that you win is

18)

1 , and if you 18

win, your profit is $15. If you lose, you lose $1. What is the expected value of your profit? A) -$0.94 B) -$0.11 C) $0.11 D) $0.83 19) At an airport, 78% of recent flights have arrived on time. A sample of 11 flights is

studied. Find the probability that exactly 7 of them were on time. A) 0.0030 B) 0.8642 C) 0.0014

19)

D) 0.1358

20) It is estimated that 45% of households own a riding lawn mower. A sample of 15

20)

households is studied. What is the probability that exactly 7 of these own a riding lawn mower? A) 0.2013 B) 0.1647 C) 0.8353 D) 0.7987 21) An environmental scientist obtains a sample of water from an irrigation canal that

21)

contains a certain type of bacteria at a concentration of 4 per milliliter. What is the probability that there will be exactly 8 bacteria in a 4-milliliter sample? A) 0.0060 B) 0.9940 C) 0.0298 D) 0.0120 22) The number of typographical errors in a document follows a Poisson distribution with a

22)

mean of 2 errors per page. Let X represent the number of errors on 4 pages. Find P(5). A) 0.0916 B) 0.0361 C) 0.9639 D) 0.1221 23) An investor is considering a $25,000 investment in a start-up company. She estimates

23)

that she has probability 0.15 of a $20,000 loss, probability 0.1 of a $30,000 profit, probability 0.25 of a $40,000 profit, and probability 0.5 of breaking even (a profit of $0). What is the expected value of the profit? A) $22,500 B) $16,667 C) $10,000 D) $16,000 24) An investor is considering a $25,000 investment in a start-up company. She estimates

24)

that she has probability 0.05 of a $15,000 loss, probability 0.1 of a $20,000 loss, probability 0.25 of a $30,000 profit, and probability 0.6 of breaking even (a profit of $0). What is the expected value of the profit? A) $19,750 B) $10,250 C) -$1667 D) $4750 25) The Australian sheep dog is a breed renowned for its intelligence and work ethic. It is

estimated that 25% of adult Australian sheep dogs weigh 65 pounds or more. A sample of 14 adult dogs is studied. What is the standard deviation of the number of dogs who weigh 65 lb or more? A) 3.5 B) 2.625 C) 1.6202 D) 14

25)

26) The Australian sheep dog is a breed renowned for its intelligence and work ethic. It is

26)

estimated that 40% of adult Australian sheep dogs weigh 65 pounds or more. A sample of 12 adult dogs is studied. What is the probability that exactly 3 of them weigh 65 lb or more? A) 0.9875 B) 0.0125 C) 0.8581 D) 0.1419 27) It is estimated that 40% of households own a riding lawn mower. A sample of 13

27)

households is studied. What is the mean number of households who own a riding mower? A) 3.12 B) 1.7664 C) 13 D) 5.2 28) Determine whether the random variable described is discrete or continuous.

28)

The length in seconds of a randomly-selected TV commercial A) discrete B) continuous 29) The number of customers in a line at a supermarket express checkout counter is a

29)

random variable with the following probability distribution. x P(x)

0 0.10

1 0.23

Find P(2 or fewer). A) 0.33

2 0.28

3 0.16

4 0.07

5 0.16

B) 0.28

C) 0.67

D) 0.61

30) Determine whether the table represents a discrete probability distribution.

30)

x P(x) -1 0.4 0 0.3 1 0.1 2 0.35 A) Yes

B) No

31) A die is rolled 11 times. Let X be the sum of the numbers obtained.

Is this a binomial distribution, and if so, what is the number of trials? A) Binomial, n = 6 B) Binomial, n = 11 C) Not binomial

31)

32) A survey asked 870 people how many times per week they dine out at a restaurant. The

32)

results are presented in the following table. Number of Times Frequency 0 124 1 249 2 245 3 121 4 80 5 20 6 28 7 3 Total 870 Consider the 870 people to be a population. Let X be the number of times per week a person dines out for a person sampled at random from this population. Find the probability that a person dines out 4 or more times per week. A) 0.059 B) 0.151 C) 0.849 D) 0.611 33) Determine whether the random variable described is discrete or continuous.

The total value of a set of coins A) discrete

33)

B) continuous

34) Last year, a manufacturer produced 200,000 DVD players. Of these, approximately 2%

34)

were defective. Assume that a simple random sample of n = 130 players is drawn. Use the Poisson approximation to the binomial distribution to compute the mean number of DVD players that were defective. A) 25.1 B) 1.6 C) 2 D) 2.6 35) At an airport, 77% of recent flights have arrived on time. A sample of 11 flights is

35)

studied. Find the probability that no more than 4 of them were on time. A) 0.0046 B) 0.0039 C) 0.9954 D) 0.9961 36) Determine the indicated probability for a binomial experiment with the given number of

trials n and the given success probability p. n =8, p = 0.6, P(3 or fewer) A) 0.1737 B) 0.0498

C) 0.4059

D) 0.8263

37) A student takes a true-false test that has 14 questions and guesses randomly at each

answer. Let X be the number of questions answered correctly. Find P(5) A) 0.1222 B) 0.0001 C) 0.0611 D) 0.1833

36)

37)

38) The number of customers in a line at a supermarket express checkout counter is a

38)

random variable with the following probability distribution. x P(x)

0 0.08

1 0.26

2 0.32

3 0.16

4 0.11

5 0.07

Find the probability that there are fewer than four people in line. A) 0.82 B) 0.18 C) 0.93

D) 0.11

39) The Australian sheep dog is a breed renowned for its intelligence and work ethic. It is

39)

estimated that 45% of adult Australian sheep dogs weigh 65 pounds or more. A sample of 16 adult dogs is studied. What is the probability that no more than 3 of them weigh 65 lb or more? A) 0.0066 B) 0.9934 C) 0.9719 D) 0.0281 40) The number of typographical errors in a document follows a Poisson distribution with a

40)

mean of 4 errors per page. Let X represent the number of errors on 2 pages. Find x. A) 2.8 B) 4 C) 8 D) 3.8 41) Determine the indicated probability for a binomial experiment with the given number of

trials n and the given success probability p. n = 11, p = 0.7, P(Fewer than 4) A) 0.0216 B) 0.0043

C) 0.9957

41)

D) 0.0006

42) Last year, a manufacturer produced 1,950,000 DVD players. Of these, approximately 5%

42)

were defective. Assume that a simple random sample of n = 230 players is drawn. Use the Poisson approximation to the binomial distribution to compute the probability that exactly nineteen of the 230 DVD players were defective. A) 0.0826 B) 0.0068 C) 0.0119 D) 0.0196 43) At an airport, 77% of recent flights have arrived on time. A sample of 11 flights is

studied. What is the mean number of flights that are on time? A) 2.53 B) 2.91 C) 1.95

D) 8.47

44) Determine the indicated probability for a Poisson random variable with the given values

of and t. = 0.9, t = 3, P(Less than 3) A) 0.4936 B) 0.7141

C) 0.5064

C) 0.5665 9

44)

D) 0.6469

45) Determine the indicated probability for a Poisson random variable with the given values

of and t. = 0.8, t = 5, P(More than 3) A) 0.4152 B) 0.4335

43)

D) 0.2381

45)

46) Determine the indicated probability for a Poisson random variable with the given values

of and t. = 0.6, t = 7, P(No more than 3) 0.3954 A) B) 0.6196

C) 0.2102

46)

D) 0.3804

47) In a poll conducted by a survey firm, 73% of respondents said that their jobs were

47)

sometimes or always stressful. Eight workers are chosen at random. What is the mean number of workers who find their job stressful? A) 1.58 B) 1.26 C) 2.16 D) 5.84 48) Determine the indicated probability for a Poisson random variable with the given values

of and t. = 0.8, t = 3, P(2) A) 0.9569 B) 0.2613

C) 0.0431

48)

D) 0.3840

49) The number of customers in a line at a supermarket express checkout counter is a

49)

random variable with the following probability distribution. x P(x)

0 0.11

1 0.22

2 0.31

3 0.16

4 0.09

5 0.11

Compute the standard deviation x. A) 1.46 B) 4.48

C) 2.12

D) 2.23

50) In a poll conducted by a survey firm, 75% of respondents said that their jobs were

50)

sometimes or always stressful. Nine workers are chosen at random. What is the probability that less than 4 of them find their jobs stressful? A) 0.9900 B) 0.0489 C) 0.0389 D) 0.0100 51) Determine whether the table represents a discrete probability distribution.

x 5 6 7 8

P(x) 0.5 0.3 0.5 -0.3

A) Yes

B) No

51)

52) Determine the indicated probability for a binomial experiment with the given number of

trials n and the given success probability p. n = 15, p = 0.9, P(13 or more) A) 0.8159 B) 0.5490

C) 0.9444

52)

D) 0.1841

53) The following table presents the probability distribution of the number of vacations X

53)

taken last year for a randomly chosen family. Compute the mean x. x P(x)

0 0.06

A) 1.43

1 0.66

2 0.16

3 0.09

4 0.03

B) 0.71

C) 0.84

D) 1.37

54) Determine the indicated probability for a binomial experiment with the given number of

trials n and the given success probability p. n = 15, p = 0.9, P(14) A) 0.9000 B) 0.0000

C) 0.3432

54)

D) 0.2288

55) In a poll conducted by a survey firm, 76% of respondents said that their jobs were

55)

sometimes or always stressful. Eight workers are chosen at random. What is the standard deviation of the number of workers who find their jobs stressful? A) 0.43 B) 1.21 C) 1.46 D) 2.47 56) Determine whether the table represents a discrete probability distribution.

56)

x P(x) -2 0.25 -1 0.3 0 0.4 1 0.05 A) Yes

B) No

57) In a poll conducted by a survey firm, 82% of respondents said that their jobs were

57)

sometimes or always stressful. Eleven workers are chosen at random. What is the probability that more than 9 of them find their jobs stressful? A) 0.6151 B) 0.3849 C) 0.3164 D) 0.6836 58) At an airport, 78% of recent flights have arrived on time. A sample of 14 flights is

studied. Find the probability that more than 12 of them were on time. A) 0.6239 B) 0.3761 C) 0.8473 D) 0.1527

58)

59) A survey asked 818 people how many times per week they dine out at a restaurant. The

59)

results are presented in the following table. Number of Times Frequency 0 111 1 235 2 228 3 114 4 73 5 24 6 27 7 6 Total 818 Consider the 818 people to be a population. Let X be the number of times per week a person dines out for a person sampled at random from this population. Compute the mean x. A) 2.2

B) 2.3

C) 1.5

D) 2.0

60) A student takes a true-false test that has 8 questions and guesses randomly at each

60)

answer. Let X be the number of questions answered correctly. Find P(6 or more) A) 0.6367 B) 0.0352 C) 0.1445 D) 0.3633 61) At an airport, 83% of recent flights have arrived on time. A sample of 12 flights is

61)

studied. What is the standard deviation of the number of flights that are on time? A) 1.30 B) 9.96 C) 1.69 D) 0.38 62) In a lottery, you pay $1 and pick a number from 000 to 999. If your number comes up,

62)

you win $350, which is a profit of $349. If you lose, you lose $1. Your probability of winning is 0.001. What is the expected value of your profit? A) -$0.65 B) $2.50 C) $0.65 D) $0.349 63) An insurance company sells a one-year term life insurance policy to an 80-year-old

woman. The woman pays a premium of $1000. If she dies within one year, the company will pay $18,500 to her beneficiary. According to the company's statistics department, the probability that an 80-year-old woman will be alive one year later is 0.9581. Find the expected value of the insurance company's profit. A) $182.95 B) $224.85 C) -$224.85 D) -$182.95

63)

64) The Australian sheep dog is a breed renowned for its intelligence and work ethic. It is

64)

estimated that 25% of adult Australian sheep dogs weigh 65 pounds or more. A sample of 11 adult dogs is studied. What is the mean number of dogs who weigh 65 lb or more? A) 1.4361 B) 2.75 C) 2.0625 D) 11 65) Determine the indicated probability for a Poisson random variable with the given values

of and t. = 0.8, t = 4, P(At least 2) A) 0.9592 B) 0.6201

C) 0.0408

65)

D) 0.8288

66) A coin is tossed until a head appears. Let X be the number of tosses.

66)

Is this a binomial distribution, and if so, what is the number of trials? A) Not binomial B) Binomial, n = X C) Binomial, n = 2 67) It is estimated that 30% of households own a riding lawn mower. A sample of 18

67)

households is studied. What is the probability that no more than 3 of these own a riding lawn mower? A) 0.0600 B) 0.1646 C) 0.8354 D) 0.94 68) The following table presents the probability distribution of the number of vacations X

68)

taken last year for a randomly chosen family. Compute the standard deviation x. x P(x) A) 1.29

0 0.11

1 0.69

2 0.13

3 0.05

4 0.02

B) 0.59

C) 1.18

D) 0.77

69) The number of typographical errors in a document follows a Poisson distribution with a

mean of 2 errors per page. Let X represent the number of errors on 4 pages. Find P(Greater than 1). A) 0.9862 B) 0.9970 C) 0.9997 D) 0.5940

69)

70) A survey asked 808 people how many times per week they dine out at a restaurant. The

70)

results are presented in the following table. Number of Times Frequency 0 116 1 230 2 222 3 110 4 69 5 25 6 30 7 6 Total 808 Consider the 808 people to be a population. Let X be the number of times per week a person dines out for a person sampled at random from this population. Find the probability that a person does not dine out at all. A) 0.144 B) 0.285 C) 0 D) 0.428 71) The Australian sheep dog is a breed renowned for its intelligence and work ethic. It is

71)

estimated that 45% of adult Australian sheep dogs weigh 65 pounds or more. A sample of 12 adult dogs is studied. What is the probability that more than 9 of them weigh 65 lb or more? A) 0.0356 B) 0.0011 C) 0.0079 D) 0.9644 72) It is estimated that 35% of households own a riding lawn mower. A sample of 10

72)

households is studied. What is the standard deviation of the number of households who own a riding lawn mower? A) 2.275 B) 10 C) 1.5083 D) 3.5 73) The following table presents the probability distribution of the number of vacations X

taken last year for a randomly chosen family. Find the probability that a family took at least 3 vacations last year. x P(x) A) 0.89

0 0.08

1 0.66

2 0.15

3 0.09

4 0.02

B) 0.09

C) 0.11

D) 0.26

73)

74) A sample of 6000 computer monitors are examined for stuck pixels. Of them, 4074 have

74)

no stuck pixels, 1153 have one stuck pixel, 462 have two stuck pixels, 226 have three stuck pixels, and 85 have four stuck pixels. Let X be the number of stuck pixels of a monitor randomly sampled from this population. Find the probability distribution of X. x 0 1 2 3 4 A) 0.0142 0.0377 0.0770 0.1922 0.6790 P(x) B)

x P(x)

0 1 2 3 4 0.6790 0.1922 0.0770 0.0377 0.0142

x P(x)

0 1 2 3 4 0.0850 0.2260 0.4620 1.1530 4.0740

x P(x)

0 1 2 3 4 4.0740 1.1530 0.4620 0.2260 0.0850

75) A coin is tossed 14 times. Let X be the number of heads obtained.

75)

Is this a binomial distribution, and if so, what is the number of trials? A) Binomial, n = 2 B) Not binomial C) Binomial, n = 14 76) Compute the mean of the random variable with the given discrete probability

76)

distribution. x P(x) 0 0.2 15 0.05 25 0.45 30 0.3 A) 17.5

B) 121.5

C) 21

D) 11.0

77) Last year, a manufacturer produced 1,950,000 DVD players. Of these, approximately 4%

were defective. Assume that a simple random sample of n = 180 players is drawn. Use the Poisson approximation to the binomial distribution to compute the probability that fewer than four of the 180 DVD players were defective. A) 0.0255 B) 0.0712 C) 0.0464 D) 0.0719

77)

78) Ten students are chosen from a statistics class of 22 students. Let X be the number who

78)

got an "A" in the class. Is this a binomial distribution, and if so, what is the number of trials? A) Not binomial B) Binomial, n = 10 C) Binomial, n = 12 D) Binomial, n = 22 79) Fill in the missing value so that the following table represents a probability distribution.

x P(x)

-4 -3 0.19 0.28

A) 0.25

79)

-2 -1 ? 0.38 B) 0

C) 0.09

D) 0.15

80) The following table presents the probability distribution of the number of vacations X

80)

taken last year for a randomly chosen family. Find P(1 or more). x P(x) A) 0.72

0 0.09

1 0.63

2 0.18

3 0.07

4 0.03

B) 0.28

C) 0.91

D) 0.63

81) There are 4000 undergraduates registered at a certain college. Of them, 364 are taking

one course, 496 are taking two courses, 460 are taking three courses, 1512 are taking four courses, 1056 are taking five courses, and 112 are taking six courses. Let X be the number of courses taken by a student randomly sampled from this population. Find the probability distribution of X. x 1 2 3 4 5 6 A) 0.3640 0.4960 0.4600 1.5120 1.0560 0.1120 P(x) B)

x P(x)

1 2 3 4 5 6 0.0910 0.1240 0.1150 0.3780 0.2640 0.0280

x P(x)

1 2 3 4 5 6 0.1120 1.0560 1.5120 0.4600 0.4960 0.3640

x P(x)

1 2 3 4 5 6 0.0280 0.2640 0.3780 0.1150 0.1240 0.0910

81)

82) An environmental scientist obtains a sample of water from an irrigation canal that

82)

contains a certain type of bacteria at a concentration of 2 per milliliter. Find the standard deviation of the number of bacteria in a 4-milliliter sample. A) 2.8 B) 2 C) 1.4 D) 8 83) Compute the standard deviation of the random variable with the given discrete

83)

probability distribution. x P(x) 5 0.4 15 0.25 20 0.15 35 0.2 A) 11.1

B) 15.75

C) 18.75

D) 123.2

84) A survey asked 805 people how many times per week they dine out at a restaurant. The

results are presented in the following table. Number of Times Frequency 0 100 1 267 2 220 3 111 4 51 5 25 6 24 7 7 Total 805 Consider the 805 people to be a population. Let X be the number of times per week a person dines out for a person sampled at random from this population. Compute the standard deviation x. A) 1.9

B) 2.2

C) 2.1

D) 1.5

84)

Answer Key Testname: C6

1) A 2) B 3) D 4) C 5) A 6) B 7) B 8) B 9) B 10) A 11) D 12) A 13) B 14) D 15) C 16) C 17) A 18) B 19) D 20) A 21) D 22) A 23) C 24) D 25) C 26) D 27) D 28) B 29) D 30) B 31) C 32) B 33) A 34) D 35) A 36) A 37) A 38) A 39) D 40) A 41) B 42) C 43) D 44) A 45) C 46) A 47) D 48) B 49) A 50) D 18

Answer Key Testname: C6

51) B 52) A 53) D 54) C 55) B 56) A 57) B 58) D 59) D 60) C 61) A 62) A 63) B 64) B 65) D 66) A 67) B 68) D 69) B 70) A 71) C 72) C 73) C 74) B 75) C 76) C 77) D 78) A 79) D 80) C 81) B 82) A 83) A 84) D

Exam Name___________________________________

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) The following dotplots each illustrate a sample. Which sample can be treated as

approximately normal? A)

2) The following dotplot illustrates a sample. Is it reasonable to treat this as a sample from

an approximately normal population?

A) No

B) Yes

3) The following histogram illustrates a sample. Is it reasonable to treat this as a sample

from an approximately normal population?

A) No

B) Yes

4) The following normal quantile plots each illustrate a sample. Which sample can be

treated as approximately normal? A)

5) The following figure is a normal curve that represents the heights, in inches, of adult

women in the United States.

Find the proportion of women who are between 61 and 67 inches tall. A) 0.0985 B) 0.2005 C) 0.9015

D) 0.7010

6) The waiting time at a certain post office is uniformly distributed between 4 and 29

minutes. Find the probability that the waiting time is less than23 minutes. A) 0.92 B) 0.08 C) 0.24 D) 0.76

7) The following figure is a normal curve that represents the weights, in pounds, of adult

female cats of a certain breed.

Find the proportion of cats who weigh more than 11.0 pounds. A) 0.0619 B) 0.3502 C) 0.6498

D) 0.9381

8) Which of the following graphs a mean of

= -2 and a standard deviation of

= 4?

9) The probability distribution of x is called a A) population

distribution.

B) probability

C) sampling

D) normal

10) The waiting time at a certain post office is uniformly distributed between 3 and 24

minutes. Find the probability that the waiting time is between 9 and 19 minutes. A) 0.52 B) 0.79 C) 0.21 D) 0.48

10)

11) The following stem-and-leaf plots each illustrate a sample. Which sample can be treated

11)

as approximately normal? A)

12) Find ^ and ^ if n = 25 and p = 0.89. p p

12)

A) ^ = 0.63; ^ = 0.06387 p p

B) ^ = 0.63; ^ = 0.06258 p p

C) ^ = 0.89; ^ = 0.06387 p p

D) ^ = 0.89; ^ = 0.06258 p p

13) A population has mean

= 9 and standard deviation

of size n = 16. = 9; = 0.25 A) x

= 4;

= 4. Find

x x

= 9; = 4;

x x

and

=1 = 0.25

for samples

13)

14) The following dotplot illustrates a sample. Is it reasonable to treat this as a sample from

14)

an approximately normal population?

A) Yes

B) No

15) The time waiting for baggage at an airport is uniformly distributed between 0 and 14

15)

minutes. Find the probability that the waiting time is between 2 and 9 minutes. A) 0.50 B) 0.47 C) 0.53 D) 0.6 16) The following boxplots each illustrate a sample. Which sample can be treated as

16)

approximately normal? A)

17) The time waiting for baggage at an airport is uniformly distributed between 0 and 15

minutes. Find the probability that the waiting time is greater than 6 minutes. A) 0.44 B) 0.56 C) 0.60 D) 0.40

17)

18) Following are the temperatures, in degrees Fahrenheit, in Denver for five days in July:

Date July 21 July 22 July 23 July 24 July 25

18)

Temperature 69 75 77 84 70

Consider this to be a population. Find the population mean and the population standard deviation . A) = 75, = 5.4037 B) = 75, = 29.2 C) = 73.6, = 29.2 D) = 73.6, = 5.4037 19) Is it reasonable to treat the sample in the following normal quantile plot as coming from

an approximately normal population?

A) Yes

B) No

19)

20) The following normal quantile plot illustrates a sample. Is it reasonable to treat this as a

20)

sample from an approximately normal population?

A) No

B) Yes

21) The following stem-and-leaf plot illustrates a sample. Is it reasonable to treat this as a

21)

sample from an approximately normal population? 7 29 8 46 9 023 10 368 11 36 12 26 13 0 14 3 A) Yes

B) No

22) The following histograms each illustrate a sample. Which sample can be treated as

approximately normal? A)

22)

23) A Pew Research report indicated that 73% of teenagers aged 13–17 own smartphones. A

random sample of 150 teenagers is drawn. i. Find the mean ^ . p

ii. Find the standard deviation ^ . p

A) i. 0.73

ii. 0.0362

B) i. 0.49

C) i. 0.49

ii. 0.0362

ii. 0.0013

D) i. 0.73

ii. 0.0013

23)

24) The following stem-and-leaf plot represents a sample from a population. Is it reasonable

24)

to assume that this population is approximately normal? 1 14589 2 0159 3 24 4 39 5 36 6 3 7 8 3 9 9 A) No

B) Yes

25) For the following dotplot, determine whether it is reasonable to treat the sample as

25)

coming from an approximately normal population.

A) Yes

B) No

26) The following figure is a normal curve that represents the heights, in inches, of adult

26)

women in the United States.

Find the proportion of women who are more than 61 inches tall. A) 0.0985 B) 0.7995 C) 0.9015

D) 0.2005

27) The time waiting for baggage at an airport is uniformly distributed between 0 and 20

minutes. Find the probability that the waiting time is less than 8 minutes. A) 0.40 B) 0.38 C) 0.60 D) 0.62

27)

28) The following boxplot illustrates a sample. Is it reasonable to treat this as a sample from

28)

an approximately normal population?

A) Yes

B) No

29) The following histogram illustrates a sample. Is it reasonable to treat this as a sample

29)

from an approximately normal population?

A) No

B) Yes

30) The following normal quantile plot illustrates a sample. Is it reasonable to treat this as a

sample from an approximately normal population?

A) No

B) Yes

30)

31) Which of the following graphs a mean of

= 3 and a standard deviation of

= 6?

31)

32) Find ^ and ^ if n = 230 and p = 0.435. p p

32)

A) ^ = 0.435; ^ = 0.03269 p p

B) ^ = 0.308; ^ = 0.03276 p p

C) ^ = 0.308; ^ = 0.03269 p p

D) ^ = 0.435; ^ = 0.03276 p p

33) For each of the following histograms, determine whether it is reasonable to treat the

33)

sample as coming from an approximately normal population.

A) No

B) Yes

34) The Institute for College Access and Success reported that 68% of college students in a

34)

recent year graduated with student loan debt. A random sample of 85 graduates is drawn. i. Find the mean ^ . p

ii. Find the standard deviation ^ . p

A) i. 0.75

ii. 0.0022

B) i. 0.75

C) i. 0.71

ii. 0.0466

D) i. 0.71

ii. 0.0022

35) The following boxplot illustrates a sample. Is it reasonable to treat this as a sample from

an approximately normal population?

A) Yes

B) No

35)

36) The following figure is a normal curve that represents the weights, in pounds, of adult

36)

female cats of a certain breed.

Find the proportion of cats who weigh less than 8.5 pounds. A) 0.0619 B) 0.6498 C) 0.9381

D) 0.3502

37) Following are the ages of the Grammy award winners for Best New Artist for the years

37)

2015–2019. (Ages are given to the nearest half year, so the five ages are all different.) Year: Winner 2019: Dua Lipa 2018: Alessia Cara 2017: Chance the Rapper 2016: Meghan Trainor 2015: Sam Smith

Age 23 21 23.5 22 22.5

Consider this to be a population. Find the population mean and the population standard deviation . A) = 22.4, = 0.8602 B) = 22.7, = 0.74 C) = 22.4, = 0.74 D) = 22.7, = 0.8602 38) A population has mean

= 17 and standard deviation

samples of size n = 16. = 17; = 1.13 A) x

= 17;

= 4.50

x x

= 18. Find

= 18; = 4;

x x

= 4.50

= 1.13

and

for

38)

39) The following stem-and-leaf plot illustrates a sample. Is it reasonable to treat this as a

39)

sample from an approximately normal population? 0 37 1 36 2 0022356 3 1456 4 4 5 5 6 35 7 13 8 35 9 3 10 11 9 A) No

B) Yes

40) The following figure is a normal curve that represents the weights, in pounds, of adult

40)

female cats of a certain breed.

Find the proportion of cats who weigh between 8.5 and 11 pounds. A) 0.9381 B) 0.6498 C) 0.4121

D) 0.5879

41) The waiting time at a certain post office is uniformly distributed between 8 and 23

minutes. Find the probability that the waiting time is greater than 14 minutes. A) 0.61 B) 0.60 C) 0.40 D) 0.39

41)

42) 0.The following figure is a normal curve that represents the heights, in inches, of adult

42)

women in the United States.

Find the proportion of women who are less than 61 inches tall. A) 0.7010 B) 0.0985 C) 0.2005

D) 0.9015

43) The following boxplot represents a sample from a population. Is it reasonable to assume

43)

that this population is approximately normal?

A) Yes

B) No

44) For a particular diamond mine, 75% of the diamonds fail to qualify as "gemstone grade".

44)

A random sample of 152 diamonds is analyzed. Find the probability that less than 76% of the sample diamonds fail to qualify as gemstone grade. A) 0.3372 B) 0.6103 C) 0.3897 D) 0.6628 45) A bottler of drinking water fills plastic bottles with a mean volume of 1010 milliliters

45)

(mL) and standard deviation 6 mL. The fill volumes are normally distributed. What proportion of bottles have volumes greater than 1008 mL? A) 0.6293 B) 1.0000 C) 0.9901 D) 0.6331 46) Use technology to solve the following problem: A recent study reported that diastolic

blood pressures of adult women in the United States are approximately normally distributed with mean 80.9 and standard deviation 9.7. What proportion of women have blood pressures higher than 88.4? A) 0.2197 B) 0.3901 C) 0.7803 D) 0.6099

46)

47) Using technology, use the normal approximation to find the indicated probability. The

47)

sample size is n, the population proportion of successes is p, and X is the number of successes in the sample. n = 94, p = 0.59: P(X > 53) A) 0.3779 B) 0.6595 C) 0.6221 D) 0.6848 48) Use the normal approximation to find the indicated probability. The sample size is n, the

48)

population proportion of successes is p, and X is the number of successes in the sample. n = 88, p = 0.46: P(X 43) A) 0.7704 B) 0.7422 C) 0.7224 D) 0.2578 49) Use technology to solve the following problem: For a particular diamond mine, 82% of

49)

the diamonds fail to qualify as "gemstone grade". A random sample of 93 diamonds is analyzed. Find the probability that the proportion of the sample diamonds that fail to qualify as gemstone grade is between 0.77 and 0.86. A) 0.8953 B) 0.7376 C) 0.8423 D) 0.1047 50) A sample of size 56 will be drawn from a population with mean 31 and standard

deviation 7. Find the probability that x will be less than 32. A) 0.8577 B) 0.1423 C) 0.8106 51) A normal population has a mean

= 33 and standard deviation

the population is less than 44? A) 0.1112 B) 1.0000

C) 0.8888

D) 0.8212

= 9. What proportion of

B) 0.4987

C) 0.0682

51)

D) 0.8554

52) Find the area under the standard normal curve that lies between z = -1.5 and z = 3. A) 0.5013

50)

52)

D) 0.9318

53) A survey reported that in a recent year, the mean serum cholesterol level in milligrams

53)

per deciliter for U.S. adults was 202 with a standard deviation of 45. A random sample of 112 adults was chosen. What is the probability that the mean cholesterol level is between 197 and 206? A) 0.7074 B) 0.2926 C) 0.8264 D) 0.9400 54) Use technology to solve the following problem: The mean annual income for people in a

certain city (in thousands of dollars) is 44, with a standard deviation of 42. A pollster draws a sample of 44 people to interview. Find the 14th percentile of the sample mean. A) 35.2 thousand dollars B) 33.8 thousand dollars C) 39.7 thousand dollars D) 37.2 thousand dollars

54)

55) Find the shaded area under the standard normal curve.

A) 0.0528

B) 0.8944

55)

C) 0.1056

D) 0.3944

56) Using technology, use the normal approximation to find the indicated probability. The

56)

sample size is n, the population proportion of successes is p, and X is the number of successes in the sample. n = 85, p = 0.34: P(X 38) A) 0.0197 B) 0.0245 C) 0.9803 D) 0.0281 57) Compact fluorescent bulbs are more energy-efficient than incandescent bulbs, but they

57)

take longer to reach full brightness. The time it takes for a compact fluorescent bulb to reach full brightness is normally distributed with mean 29.9 seconds and standard deviation 4.1 seconds. Find and interpret the z-score for x = 26.4. A) z = 0.75: the time to reach full brightness is 0.75 standard deviations below the mean. B) z = 0.75: the time to reach full brightness is 0.75 standard deviations above the mean. C) z = -0.85: the time to reach full brightness is 0.85 standard deviations above the mean. D) z = -0.85: the time to reach full brightness is 0.85 standard deviations below the mean. 58) Find the z-scores that bound the middle 86% of the area under the standard normal curve. A) -1.68, 1.68

B) -1.52, 1.52

C) -1.48, 1.48

58)

D) -1.29, 1.29

59) Use technology to solve the following problem: A sample of size 85 will be drawn from

59)

a population with mean 25 and standard deviation 14. Find the probability that x will be between 22 and 27. A) 0.0939 B) 0.0241 C) 0.8820 D) 0.8930 60) Use the Central Limit Theorem to find the indicated probability. The sample size is n, ^

the population proportion is p, and the sample proportion is p. ^

n = 116, p = 0.12; P( p < 0.08) A) 0.0918 B) 0.1093

C) 0.1292 19

D) 0.1112

60)

61) The lifetime of a certain type of automobile tire (in thousands of miles) is normally

61)

distributed with mean = 38 and standard deviation = 4. What proportion of tires have lifetimes greater than 39 thousand miles? A) 0.4013 B) 0.2994 C) 0.5987 D) 0.7006 62) Use the Central Limit Theorem to find the indicated probability. The sample size is n,

62)

the population proportion is p, and the sample proportion is p. ^

n = 106, p = 0.28; P( p > 0.34) A) 0.0594 B) 0.9162

C) 0.0694

D) 0.0838

63) The following figure is a probability density curve that represents the lifetime, in

63)

months, of a certain type of laptop battery.

Find the proportion of batteries with lifetimes between 10 and 20 months. A) 0.20 B) 0.26 C) 0.06 D) 0.74 64) Use technology to solve the following problem: The weights of 6-week-old poults

64)

(juvenile turkeys) are normally distributed with a mean 8.6 pounds and standard deviation 1.3 pounds. Find the first quartile of the weight. A) 7.73 lb B) 8.50 lb C) 6.96 lb D) 9.28 lb 65) Use the normal approximation to find the indicated probability. The sample size is n, the

65)

population proportion of successes is p, and X is the number of successes in the sample. n = 103, p = 0.74: P(X > 75) A) 0.5636 B) 0.4641 C) 0.5948 D) 0.5359 66) Use the normal approximation to find the indicated probability. The sample size is n, the

population proportion of successes is p, and X is the number of successes in the sample. n = 96, p = 0.61: P(55 < X < 68) A) 0.9693 B) 0.2611 C) 0.0307 D) 0.7082

66)

67) Find the shaded area under the standard normal curve.

A) 0.9454

B) 0.9878

C) 0.0546

67)

D) 0.0273

68) Use technology to solve the following problem: A certain car model has a mean gas

68)

mileage of 28 miles per gallon (mpg) with a standard deviation 4 mpg. A pizza delivery company buys 43 of these cars. What is the probability that the average mileage of the fleet is between 27.5 and 28.9 mpg? A) 0.2762 B) 0.9300 C) 0.7238 D) 0.2062 69) At a cell phone assembly plant, 83% of the cell phone keypads pass inspection. A

random sample of 117 keypads is analyzed. Find the standard deviation

69)

A) 0.97

B) 0.035

C) 0.83

D) 0.17

70) Use technology to solve the following problem: A ferry will safely accommodate 74 tons

70)

of passenger cars. Assume that the mean weight of a passenger car is 1.9 tons with standard deviation 0.6 tons. If a random sample of 36 cars are loaded onto the ferry, what is the probability that the maximum safe weight will be exceeded? A) 0.0770 B) 0.9401 C) 0.0413 D) 0.0599 71) Using technology, use the Central Limit Theorem to find the indicated probability. The

71)

sample size is n, the population proportion is p, and the sample proportion is p. ^

n = 193, p = 0.81; P(0.79 < p < 0.82) A) 0.6384 B) 0.3616

C) 0.2394

D) 0.3990

72) Use technology to solve the following problem: Airlines often sell more tickets for a

flight than there are seats because some ticket holders do not show up for the flight. Assume that an airplane has 100 seats for passengers and that the probability that a person holding a ticket appears for the flight is 0.95. If the airline sells 104 tickets, what is the probability that everyone who appears for the flight will get a seat? A) 0.7071 B) 0.6967 C) 0.7778 D) 0.6682

72)

73) Find the shaded area under the standard normal curve.

A) 0.0793

B) 0.8413

C) 0.3413

73)

D) 0.1587

74) Using technology, use the Central Limit Theorem to find the indicated probability. The

74)

sample size is n, the population proportion is p, and the sample proportion is p. ^

n = 182, p = 0.58; P( p > 0.61) A) 0.2061 B) 0.1587

C) 0.7939

D) 0.1635

75) For a particular diamond mine, 83% of the diamonds fail to qualify as "gemstone grade".

75)

A random sample of 101 diamonds is analyzed. Find the probability that more than 79% of the sample diamonds fail to qualify as gemstone grade. A) 0.8577 B) 0.1423 C) 0.1562 D) 0.8438 76) At a cell phone assembly plant, 76% of the cell phone keypads pass inspection. A

76)

random sample of 96 keypads is analyzed. Find the probability that more than 72% of the sample keypads pass inspection. A) 0.2005 B) 0.1788 C) 0.7995 D) 0.8212 77) Find the area under the standard normal curve to the left of z = -2.2. A) 0.0139

B) 0.0070

C) 0.9861

77) D) 0.4861

78) Find the z-scores that bound the middle 80% of the area under the standard normal curve. A) -0.96, 0.96

B) -1.18, 1.18

C) -1.28, 1.28

D) -1.23, 1.23

79) Use technology to solve the following problem: A survey reported that in a recent year,

the mean serum cholesterol level in milligrams per deciliter for U.S. adults was 200 with a standard deviation of 35. A random sample of 120 adults was chosen. What is the probability that the mean cholesterol level is less than 197? A) 0.4658 B) 0.8261 C) 0.5342 D) 0.1739

78)

79)

80) Use technology to solve the following problem: The mean annual income for people in a

80)

certain city (in thousands of dollars) is 41, with a standard deviation of 32. A pollster draws a sample of 58 people to interview. What is the probability that the sample mean income is less than 40 (thousands of dollars)? A) 0.4570 B) 0.4059 C) 0.3416 D) 0.5430 81) A normal distribution has mean

81)

82) Use technology to solve the following problem: A gardener buys a package of seeds.

82)

= 18 and standard deviation = 4. Find and interpret the z-score for x = 14. A) z = -1: a value of 14 is one standard deviation below the mean. B) z = -4: a value of 14 is one standard deviation below the mean. C) z = 22: a value of 14 is one standard deviation above the mean. D) z = 1: a value of 14 is one standard deviation above the mean.

Seventy-nine percent of seeds of this type germinate. The gardener plants 100 seeds. Approximate the probability that the number of seeds that germinate is between 75 and 87 exclusive. A) 0.1951 B) 0.2279 C) 0.7721 D) 0.9672 83) Find the area under the standard normal curve to the right of z = 1.2. A) 0.3849

B) 0.1151

C) 0.8849

83) D) 0.0576

84) A bottler of drinking water fills plastic bottles with a mean volume of 1006 milliliters

84)

(mL) and standard deviation 4 mL. The fill volumes are normally distributed. What proportion of bottles have volumes between 1004 mL and 1005 mL? A) 0.3085 B) 0.0928 C) 0.4013 D) 0.4008 85) A survey reported that in a recent year, the mean serum cholesterol level in milligrams

85)

per deciliter for U.S. adults was 201 with a standard deviation of 44. A random sample of 92 adults was chosen. Find the 33rd percentile of the sample mean. A) 181.6 B) 200.8 C) 199.0 D) 202.5 86) For a particular diamond mine, 75% of the diamonds fail to qualify as "gemstone grade".

A random sample of 101 diamonds is analyzed. Find the mean

86)

A) 0.96

B) 0.75

C) 0.25

D) 0.043

87) Find the z-scores that bound the middle 70% of the area under the standard normal curve. A) -0.71, 0.71

B) -0.68, 0.68

C) -1.04, 1.04

D) -0.89, 0.89

87)

88) For a particular diamond mine, 79% of the diamonds fail to qualify as "gemstone grade".

A random sample of 94 diamonds is analyzed. Find the standard deviation

88)

A) 0.042

B) 0.21

C) 0.96

D) 0.79

89) The mean number of pets per household is 3.03 with standard deviation 1.5. A sample of

89)

56 households is drawn. Find the 62nd percentile of the sample mean. A) 3.95 B) 2.57 C) 3.65 D) 3.09 90) Use technology to solve the following problem: A recent study reported that diastolic

90)

blood pressures of adult women in the United States are approximately normally distributed with mean 80.9 and standard deviation 9.7. What proportion of women have blood pressures lower than 63.7? A) 0.9810 B) 0.0381 C) 0.9619 D) 0.0190 91) Use technology to solve the following problem: A sample of size 47 will be drawn from

91)

a population with mean 12 and standard deviation 5. Find the probability that x will be less than 13. A) 0.9148 B) 0.0852 C) 0.8982 D) 0.9280 92) Use technology to solve the following problem: At a cell phone assembly plant, 80% of

92)

the cell phone keypads pass inspection. A random sample of 110 keypads is analyzed. Find the probability that more than 83% of the sample keypads pass inspection. A) 0.7842 B) 0.2158 C) 0.1958 D) 0.8042 93) Use technology to solve the following problem: A normal population has a mean

and standard deviation be greater than 36? A) 0.2023

= 31 = 6. What is the probability that a randomly chosen value will B) 0.7977

C) 0.7563

93)

D) 0.8334

94) Airlines often sell more tickets for a flight than there are seats because some ticket

94)

holders do not show up for the flight. Assume that an airplane has 160 seats for passengers and that the probability that a person holding a ticket appears for the flight is 0.95. If the airline sells 165 tickets, what is the probability that everyone who appears for the flight will get a seat? A) 0.8531 B) 0.9099 C) 0.8686 D) 0.8708 95) According to a recent study, the weight of male babies less than two months old in the

United States is normally distributed with mean 10.9 pounds and standard deviation 2.7 pounds. What proportion of babies weigh less than 12.1 pounds? A) 0.6650 B) 0.3350 C) 0.3300 D) 0.6700

95)

96) Use technology to solve the following problem: A recent study reported that diastolic

96)

blood pressures of adult women in the United States are approximately normally distributed with mean 79.9 and standard deviation 9.5. What proportion of women have blood pressures between 68.2 and 72.1? A) 0.0968 B) 0.4105 C) 0.3149 D) 0.9032 97) Using technology, use the normal approximation to find the indicated probability. The

97)

sample size is n, the population proportion of successes is p, and X is the number of successes in the sample. n = 76, p = 0.73: P(X 53) A) 0.3045 B) 0.2771 C) 0.3258 D) 0.6955 98) Find the area under the standard normal curve that lies outside the interval between

z = -0.3 and z = 0.2. A) 0.9207

B) 0.8028

C) 0.0793

D) 0.1972

99) A sample of size 90 will be drawn from a population with mean 21 and standard

deviation 15. Find the probability that x will be between 20 and 23. A) 0.2643 B) 0.1038 C) 0.6318

98)

99)

D) 0.6564

100) Use technology to solve the following problem: According to a recent study, the weight

100)

of male babies less than two months old in the United States is normally distributed with mean 11.8 pounds and standard deviation 2.4 pounds. What proportion of babies weigh more than 13.7 pounds? A) 0.6071 B) 0.7857 C) 0.2143 D) 0.3929 101) Use technology to solve the following problem: A bottler of drinking water fills plastic

101)

bottles with a mean volume of 1000 milliliters (mL) and standard deviation 7 mL. The fill volumes are normally distributed. What proportion of bottles have volumes less than 1009 mL? A) 0.8880 B) 0.9007 C) 1.0000 D) 0.9995 102) Use technology to solve the following problem: The weights of 6-week-old poults

102)

(juvenile turkeys) are normally distributed with a mean 9.1 pounds and standard deviation 1.2 pounds. A turkey farmer wants to provide a money-back guarantee that her 6-week poults will weigh at least a certain amount. What weight should she guarantee so that she will have to give her customer's money back only 1% of the time? A) 6.93 lb B) 7.56 lb C) 5.67 lb D) 6.30 lb 103) At a cell phone assembly plant, 76% of the cell phone keypads pass inspection. A

random sample of 146 keypads is analyzed. Find the probability that less than 77% of the sample keypads pass inspection. A) 0.6480 B) 0.6103 C) 0.3897 D) 0.3520 25

103)

104) Find the z-score for which the area to the left is 0.93. A) 1.48

B) 1.65

C) 1.50

104) D) 1.27

105) Using technology, use the normal approximation to find the indicated probability. The

105)

sample size is n, the population proportion of successes is p, and X is the number of successes in the sample. n = 103, p = 0.61: P(54 X 70) A) 0.0606 B) 0.0297 C) 0.9096 D) 0.9394 106) Find the z-score for which the area to the right is 0.91. A) -1.34

B) -1.56

C) -1.23

106) D) -1.09

107) A certain car model has a mean gas mileage of 27 miles per gallon (mpg) with a standard

107)

deviation 4 mpg. A pizza delivery company buys 55 of these cars. What is the probability that the average mileage of the fleet is between 26.7 and 27.1 mpg? A) 0.2876 B) 0.7124 C) 0.5753 D) 0.2877 108) Use technology to solve the following problem: For a particular diamond mine, 77% of

108)

the diamonds fail to qualify as "gemstone grade". A random sample of 99 diamonds is analyzed. Find the probability that more than 78% of the sample diamonds fail to qualify as gemstone grade. A) 0.4065 B) 0.3796 C) 0.5935 D) 0.6204 109) A ferry will safely accommodate 77 tons of passenger cars. Assume that the mean weight

109)

of a passenger car is 2 tons with standard deviation 0.5 tons. If a random sample of 36 cars are loaded onto the ferry, what is the probability that the maximum safe weight will be exceeded? A) 0.0322 B) 0.0427 C) 0.9525 D) 0.0475 110) The mean annual income for people in a certain city (in thousands of dollars) is 45, with

110)

a standard deviation of 29. A pollster draws a sample of 45 people to interview. Find the 51st percentile of the sample mean. A) 45.1 thousand dollars B) 42.1 thousand dollars C) 41.7 thousand dollars D) 47.4 thousand dollars 111) Using technology, use the normal approximation to find the indicated probability. The

sample size is n, the population proportion of successes is p, and X is the number of successes in the sample. n = 92, p = 0.54: P(47 < X < 60) A) 0.3242 B) 0.9800 C) 0.6558 D) 0.0200

111)

112) The weights of 6-week-old poults (juvenile turkeys) are normally distributed with a mean

112)

8.9 pounds and standard deviation 1.7 pounds. A turkey farmer wants to provide a money-back guarantee that her 6-week poults will weigh at least a certain amount. What weight should she guarantee so that she will have to give her customer's money back only 1% of the time? A) 4.45 lb B) 3.95 lb C) 5.43 lb D) 4.94 lb 113) A gardener buys a package of seeds. Seventy-four percent of seeds of this type

113)

germinate. The gardener plants 130 seeds. Approximate the probability that fewer than 95 seeds germinate. A) 0.6331 B) 0.7157 C) 0.2843 D) 0.3669 114) A bottler of drinking water fills plastic bottles with a mean volume of 1007 milliliters

114)

(mL) and standard deviation 7 mL. The fill volumes are normally distributed. What proportion of bottles have volumes less than 998 mL? A) 0.0985 B) 0.9966 C) 0.9306 D) 1.0000 115) According to a recent study, the weight of male babies less than two months old in the

115)

United States is normally distributed with mean 11.5 pounds and standard deviation 2.8 pounds. What proportion of babies weigh more than 13.9 pounds? A) 0.4026 B) 0.5974 C) 0.8051 D) 0.1949 116) Use technology to solve the following problem: At a cell phone assembly plant, 75% of

116)

the cell phone keypads pass inspection. A random sample of 106 keypads is analyzed. Find the probability that the proportion of the sample keypads that pass inspection is between 0.72 and 0.77. A) 0.7622 B) 0.6828 C) 0.4450 D) 0.2378 117) Use technology to solve the following problem: A survey reported that in a recent year,

117)

the mean serum cholesterol level in milligrams per deciliter for U.S. adults was 198 with a standard deviation of 36. A random sample of 108 adults was chosen. What is the probability that the mean cholesterol level is between 194 and 201? A) 0.3173 B) 0.8068 C) 0.6827 D) 0.8660 118) Use technology to solve the following problem: A normal population has a mean

and standard deviation A) 12.84

= 3. What is the 61st percentile of the population? B) 10.27 C) 11.56 D) 15.41

= 12

118)

119) Use technology to solve the following problem: A certain car model has a mean gas

119)

mileage of 33 miles per gallon (mpg) with a standard deviation 4 mpg. A pizza delivery company buys 42 of these cars. What is the probability that the average mileage of the fleet is greater than 33.8 mpg? A) 0.0975 B) 0.0449 C) 0.8149 D) 0.1851 120) A survey reported that in a recent year, the mean serum cholesterol level in milligrams

120)

per deciliter for U.S. adults was 199 with a standard deviation of 45. A random sample of 112 adults was chosen. What is the probability that the mean cholesterol level is less than 195? A) 0.4641 B) 0.5359 C) 0.8264 D) 0.1736 121) According to a recent study, the weight of male babies less than two months old in the

121)

United States is normally distributed with mean 12.0 pounds and standard deviation 2.8 pounds. What proportion of babies weigh between 9.1 and 12.3 pounds? A) 0.6930 B) 0.3946 C) 1.1500 D) 0.6054 122) Use the normal approximation to find the indicated probability. The sample size is n, the

122)

population proportion of successes is p, and X is the number of successes in the sample. n = 85, p = 0.42: P(29 X 42) A) 0.0681 B) 0.0571 C) 0.8748 D) 0.9319 123) The weights of 6-week-old poults (juvenile turkeys) are normally distributed with a mean

123)

8.6 pounds and standard deviation 1.5 pound(s). Find the 67th percentile of the weights. A) 7.41 lb B) 10.19 lb C) 8.33 lb D) 9.26 lb 124) Use technology to solve the following problem: The lifetime of a certain type of

124)

automobile tire (in thousands of miles) is normally distributed with mean = 39 and standard deviation = 4. What proportion of tires have lifetimes of less than 41 thousand miles? A) 0.3085 B) 0.6543 C) 0.3457 D) 0.6915 125) A normal population has a mean

= 32 and standard deviation = 10. What is the probability that a randomly chosen value will be greater than 43? A) 0.8643 B) 0.1357 C) 0.6915 D) 0.8485

125)

126) The following figure is a probability density curve that represents the lifetime, in

126)

months, of a certain type of laptop battery.

Find the proportion of batteries with lifetimes less than 20 months. A) 0.24 B) 0.25 C) 0.49

D) 0.75

127) Use the normal approximation to find the indicated probability. The sample size is n, the

127)

population proportion of successes is p, and X is the number of successes in the sample. n = 104, p = 0.75: P(X 72) A) 0.9357 B) 0.0808 C) 0.9192 D) 0.9292 128) The mean annual income for people in a certain city (in thousands of dollars) is 46, with

128)

a standard deviation of 42. A pollster draws a sample of 51 people to interview. What is the probability that the sample mean income is less than 41 (thousands of dollars)? A) 0.1711 B) 0.2266 C) 0.1977 D) 0.7734 129) Use technology to solve the following problem: A sample of size 35 will be drawn from

129)

a population with mean 80 and standard deviation 8. Find the 23rd percentile of x. A) 82.9 B) 80.2 C) 82.8 D) 79.0 130) A certain car model has a mean gas mileage of 32 miles per gallon (mpg) with a standard

130)

deviation 5 mpg. A pizza delivery company buys 53 of these cars. What is the probability that the average mileage of the fleet is greater than 31 mpg? A) 0.0314 B) 0.9686 C) 0.9279 D) 0.8770 131) A normal population has a mean

= 12 and standard deviation

percentile of the population? A) 12.84 B) 11.56

C) 15.41

= 3. What is the 61st D) 10.27

132) The lifetime of a certain type of automobile tire (in thousands of miles) is normally

distributed with mean = 42 and standard deviation = 5. What proportion of tires have lifetimes of less than 45 thousand miles? A) 0.6371 B) 0.7257 C) 0.2743 D) 0.3629 29

131)

132)

133) Use technology to solve the following problem: A normal population has a mean

= 35

133)

134) Use technology to solve the following problem: For a particular diamond mine, 75% of

134)

and standard deviation A) 0.7625

= 8. What proportion of the population is less than 33? B) 1.0000 C) 0.5987 D) 0.4013

the diamonds fail to qualify as "gemstone grade". A random sample of 242 diamonds is analyzed. Find the probability that less than 76% of the sample diamonds fail to qualify as gemstone grade. A) 0.3597 B) 0.3194 C) 0.6403 D) 0.6806 135) The following figure is a probability density curve that represents the lifetime, in

135)

months, of a certain type of laptop battery.

What is the probability that a randomly chosen battery lasts longer than 20 months? A) 0.09 B) 0.34 C) 0.25 D) 0.66 136) Use technology to solve the following problem: The mean number of pets per household

136)

is 2.91 with standard deviation 1.7. A sample of 50 households is drawn. Find the 12th percentile of the sample mean. A) 1.96 B) 2.63 C) 3.50 D) 3.46 137) Use the Central Limit Theorem to find the indicated probability. The sample size is n,

137)

the population proportion is p, and the sample proportion is p. ^

n = 174, p = 0.7; P(0.67 < p < 0.72) A) 0.5241 B) 0.2810

C) 0.7190

D) 0.1949

138) A recent study reported that diastolic blood pressures of adult women in the United

States are approximately normally distributed with mean 79.9 and standard deviation 9.7. What proportion of women have blood pressures lower than 67.2? A) 0.0951 B) 0.9049 C) 0.9525 D) 0.0475

138)

139) At a cell phone assembly plant, 76% of the cell phone keypads pass inspection. A

139)

random sample of 95 keypads is analyzed. Find the probability that the proportion of the sample keypads that pass inspection is between 0.7 and 0.8. A) 0.9147 B) 0.8186 C) 0.0853 D) 0.7332 140) Use technology to solve the following problem: A normal population has a mean

and standard deviation A) 0.0228

= 15 = 3. What proportion of the population is between 9 and 14? B) 0.3694 C) 0.6533 D) 0.3467

141) Find the shaded area under the standard normal curve.

A) 0.0628

B) 0.0314

C) 0.9372

140)

141)

D) 0.4772

142) Using technology, use the Central Limit Theorem to find the indicated probability. The

142)

sample size is n, the population proportion is p, and the sample proportion is p. ^

n = 154, p = 0.46; P( p < 0.5) A) 0.8656 B) 0.8802

C) 0.8404

D) 0.8782

143) Use technology to solve the following problem: A survey reported that in a recent year,

143)

the mean serum cholesterol level in milligrams per deciliter for U.S. adults was 193 with a standard deviation of 41. A random sample of 95 adults was chosen. Find the 9th percentile of the sample mean. A) 138.1 B) 187.4 C) 192.4 D) 193.4 144) The lifetime of a certain type of automobile tire (in thousands of miles) is normally

144)

distributed with mean = 41 and standard deviation = 7. What proportion of tires have lifetimes between 35 and 47 thousand miles? A) 0.3898 B) 1.0000 C) 1.7200 D) 0.6102 145) Use technology to solve the following problem: According to a recent study, the weight

of male babies less than two months old in the United States is normally distributed with mean 11.9 pounds and standard deviation 2.5 pounds. What proportion of babies weigh between 10.3 and 13.3 pounds? A) 0.5488 B) 0.4512 C) 1.2000 D) 0.9733

145)

146) For a particular diamond mine, 84% of the diamonds fail to qualify as "gemstone grade".

146)

A random sample of 112 diamonds is analyzed. Find the probability that the proportion of the sample diamonds that fail to qualify as gemstone grade is between 0.78 and 0.88. A) 0.8331 B) 0.9582 C) 0.0418 D) 0.8749 147) Use technology to solve the following problem: The lifetime of a certain type of

147)

automobile tire (in thousands of miles) is normally distributed with mean = 40 and standard deviation = 4. What proportion of tires have lifetimes greater than 39 thousand miles? A) 0.4013 B) 0.5987 C) 0.7994 D) 0.2006 148) A normal distribution has mean

= 45 and standard deviation

= 20. Find and interpret

148)

the z-score for x = 55. A) z = 0.25: a value of 55 is 0.25 standard deviations above the mean. B) z = -10: a value of 55 is -10 standard deviations below the mean. C) z = 0.50: a value of 55 is 0.50 standard deviations above the mean. D) z = -0.50: a value of 55 is 0.50 standard deviations below the mean. 149) Use technology to solve the following problem: A gardener buys a package of seeds.

149)

Eighty-one percent of seeds of this type germinate. The gardener plants 90 seeds. Approximate the probability that 74 or more seeds germinate. A) 0.5827 B) 0.5274 C) 0.4360 D) 0.5670 150) Use technology to solve the following problem: The mean annual income for people in a

150)

certain city (in thousands of dollars) is 46, with a standard deviation of 38. A pollster draws a sample of 44 people to interview. What is the probability that the sample mean income is between 45 and 52 (thousands of dollars)? A) 0.1475 B) 0.8525 C) 0.4218 D) 0.5782 151) Use technology to solve the following problem: A gardener buys a package of seeds.

151)

Seventy-two percent of seeds of this type germinate. The gardener plants 100 seeds. Approximate the probability that fewer than 64 seeds germinate. A) 0.9839 B) 0.0292 C) 0.0161 D) 0.9708 152) A gardener buys a package of seeds. Eighty-seven percent of seeds of this type

152)

germinate. The gardener plants 130 seeds. Approximate the probability that the number of seeds that germinate is between 104.1 and 119.1 exclusive. A) 0.9236 B) 0.9104 C) 0.0896 D) 0.0132 153) A gardener buys a package of seeds. Ninety-two percent of seeds of this type germinate.

The gardener plants 110 seeds. Approximate the probability that 99 or more seeds germinate. A) 0.9032 B) 0.9115 C) 0.8289 D) 0.8749 32

153)

154) Use technology to solve the following problem: A bottler of drinking water fills plastic

154)

bottles with a mean volume of 1010 milliliters (mL) and standard deviation 7 mL. The fill volumes are normally distributed. What proportion of bottles have volumes between 1003 mL and 1005 mL? A) 0.3682 B) 0.1587 C) 0.0788 D) 0.2375 155) At a cell phone assembly plant, 81% of the cell phone keypads pass inspection. A

random sample of 106 keypads is analyzed. Find the mean

155)

A) 0.19

B) 0.81

C) 0.96

D) 0.038

156) Use technology to solve the following problem: At a cell phone assembly plant, 85% of

156)

the cell phone keypads pass inspection. A random sample of 156 keypads is analyzed. Find the probability that less than 83% of the sample keypads pass inspection. A) 0.7256 B) 0.2744 C) 0.2421 D) 0.7579 157) A recent study reported that diastolic blood pressures of adult women in the United

157)

States are approximately normally distributed with mean 81.2 and standard deviation 9.1. What proportion of women have blood pressures higher than 85.8? A) 0.6950 B) 0.3475 C) 0.6525 D) 0.3050 158) A recent study reported that diastolic blood pressures of adult women in the United

158)

States are approximately normally distributed with mean 81.1 and standard deviation 8.9. What proportion of women have blood pressures between 73.3 and 87.6? A) 1.6100 B) 0.5779 C) 0.9567 D) 0.4221 159) Use technology to solve the following problem: A bottler of drinking water fills plastic

159)

bottles with a mean volume of 1008 milliliters (mL) and standard deviation 4 mL. The fill volumes are normally distributed. What proportion of bottles have volumes greater than 1008 mL? A) 0.5517 B) 0.5000 C) 0.9987 D) 1.0000 160) Use technology to solve the following problem: The lifetime of a certain type of

160)

automobile tire (in thousands of miles) is normally distributed with mean = 37 and standard deviation = 7. What proportion of tires have lifetimes between 38 and 43 thousand miles? A) 0.7143 B) 0.7525 C) 0.2475 D) 1.3611 161) A sample of size 45 will be drawn from a population with mean 72 and standard

deviation 7. Find the 17th percentile of x. A) 71.0 B) 66.7

C) 67.3

D) 72.7

161)

162) Using technology, use the normal approximation to find the indicated probability. The

162)

sample size is n, the population proportion of successes is p, and X is the number of successes in the sample. n = 98, p = 0.52: P(X < 54) A) 0.7302 B) 0.6821 C) 0.3038 D) 0.6962 163) Use technology to solve the following problem: The weights of 6-week-old poults

163)

(juvenile turkeys) are normally distributed with a mean 8.7 pounds and standard deviation 1.4 pound(s). Find the 34th percentile of the weights. A) 8.94 lb B) 7.32 lb C) 9.76 lb D) 8.13 lb 164) Find the z-score for which the area to the right is 0.35. A) 0.119

B) 0.05

C) 0.21

164) D) 0.39

165) The weights of 6-week-old poults (juvenile turkeys) are normally distributed with a mean

165)

8.5 pounds and standard deviation 1.8 pounds. Find the first quartile of the weight. A) 8.02 lb B) 5.83 lb C) 7.29 lb D) 8.75 lb 166) A normal population has a mean

= 30 and standard deviation of the population is between 22 and 30? A) 0.2119 B) 0.7119 C) 0.5000

= 10. What proportion D) 0.2881

167) A sample of size 53 will be drawn from a population with mean 17 and standard

deviation 15. Find the probability that x will be greater than 20. A) 0.1020 B) 0.9279 C) 0.0721

166)

167)

D) 0.0516

168) Use technology to solve the following problem: A sample of size 57 will be drawn from

168)

a population with mean 19 and standard deviation 6. Find the probability that x will be greater than 20. A) 0.0752 B) 0.8959 C) 0.0810 D) 0.1041 169) Find the z-score for which the area to the left is 0.79. A) 1.04

B) 0.64

C) 0.58

169) D) 0.81

170) The mean annual income for people in a certain city (in thousands of dollars) is 46, with

a standard deviation of 34. A pollster draws a sample of 37 people to interview. What is the probability that the sample mean income is between 44 and 52 (thousands of dollars)? A) 0.8577 B) 0.4983 C) 0.5017 D) 0.1423

170)

171) Use the normal approximation to find the indicated probability. The sample size is n, the

171)

population proportion of successes is p, and X is the number of successes in the sample. n = 76, p = 0.54: P(X < 47) A) 0.9049 B) 0.8962 C) 0.8830 D) 0.1038 172) Use technology to solve the following problem: According to a recent study, the weight

172)

of male babies less than two months old in the United States is normally distributed with mean 11.6 pounds and standard deviation 2.9 pounds. What proportion of babies weigh less than 9.5 pounds? A) 0.1172 B) 0.7655 C) 0.8828 D) 0.2345 TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 173) If the points in a normal quantile plot deviate from a straight line, then the population

173)

can be treated as approximately normal. 174) A normal curve is symmetric around its mode.

174)

175) The area under the normal curve to the left of the mode is less than 0.5

175)

176) A normal curve is wide and flat when the standard deviation is small.

176)

Answer Key Testname: C7

1) D 2) A 3) B 4) D 5) D 6) D 7) A 8) B 9) C 10) D 11) C 12) D 13) B 14) A 15) D 16) A 17) C 18) A 19) A 20) B 21) A 22) B 23) A 24) A 25) A 26) B 27) A 28) A 29) A 30) A 31) B 32) A 33) B 34) C 35) B 36) D 37) A 38) C 39) A 40) D 41) B 42) C 43) A 44) B 45) A 46) A 47) B 48) B 49) B 50) A 36

Answer Key Testname: C7

51) C 52) D 53) A 54) D 55) C 56) B 57) D 58) C 59) C 60) A 61) A 62) D 63) A 64) A 65) A 66) D 67) C 68) C 69) B 70) D 71) D 72) C 73) D 74) A 75) A 76) D 77) A 78) D 79) D 80) B 81) A 82) C 83) B 84) B 85) C 86) B 87) B 88) A 89) D 90) B 91) A 92) B 93) A 94) B 95) D 96) A 97) A 98) B 99) C 100) C 37

Answer Key Testname: C7

101) B 102) D 103) B 104) A 105) C 106) A 107) A 108) A 109) D 110) A 111) C 112) D 113) D 114) A 115) D 116) C 117) C 118) A 119) A 120) D 121) B 122) C 123) D 124) D 125) B 126) C 127) D 128) C 129) D 130) C 131) A 132) B 133) D 134) C 135) D 136) B 137) A 138) A 139) D 140) D 141) A 142) C 143) B 144) D 145) B 146) A 147) B 148) C 149) C 150) C 38

Answer Key Testname: C7

151) B 152) B 153) C 154) C 155) B 156) C 157) D 158) B 159) B 160) C 161) A 162) D 163) D 164) D 165) C 166) D 167) C 168) D 169) D 170) B 171) B 172) D 173) FALSE 174) TRUE 175) FALSE 176) FALSE

Exam Name___________________________________

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) A scientist plans to construct a 95% confidence interval for the mean length of steel rods

that are manufactured by a certain process. She will draw a simple random sample of rods and compute the confidence interval using the methods described in this section. She says, "The probability is 95% that the population mean length will be covered by the confidence interval." Is she right? A) No B) Yes 2) A simple random sample of size 25 has mean x = 15.6 and standard deviation s = 5.8.

The population is approximately normally distributed. Construct a 95% confidence interval for the population mean. A) (13.7, 17.5) B) (13.2, 18.0) C) (12.9, 18.3) D) (13.3, 17.9) 3) A pollster is going to sample a number of voters in a large city and construct a 98%

confidence interval for the proportion who support the incumbent candidate for mayor. Find a sample size so that the margin of error will be no larger than 0.02. A) 3382 B) 1691 C) 2401 D) 1692 4) Find the critical values for a 95% confidence interval using the chi-square distribution

with 13 degrees of freedom. A) 5.892, 22.362 B) 4.404, 23.337

C) 5.226, 21.026

D) 5.009, 24.736

5) A sample of size n = 33 has sample mean x = 34.87 and sample standard deviation

s = 19.1. i. Construct a 98% confidence interval for the population mean . ii. If the confidence level were 95%, would the confidence interval be narrower or wider? A) i. (23.68, 46.06) B) i. (26.73, 43.01) ii. Narrower ii. Wider i. (26.73, 43.01) C) D) i. (23.68, 46.06) ii. Narrower ii. Wider 6) In a simple random sample of 150 children, 25 had reading skills above their grade level.

Construct a 95% confidence interval for the proportion of children who have reading skills above their grade level. A) (0.043, 0.523) B) 0.141, 0.339) C) (0.197, 0.283) D) (0.130, 0.350)

7) In a preliminary study, a simple random sample of 100 computer chips was tested, and

18 of them were found to be defective. Now another sample will be drawn in order to construct a 95% confidence interval for the proportion of chips that are defective. Use the results of the preliminary study to estimate the sample size needed so that the confidence interval will have a margin of error of 0.05. A) 320 B) 160 C) 227 D) 385 8) An educator wants to construct a 98% confidence interval for the proportion of

elementary schoolchildren in Colorado who are proficient in reading. i. The results of a recent statewide test suggested that the proportion is 0.70. Using this estimate, what sample size is needed so that the confidence interval will have a margin of error of 0.03? ii. Estimate the sample size needed if no estimate of p is available. A) i. 1263 B) i. 897 C) i. 632 D) i. 1549 ii. 1503 ii. 1068 ii. 752 ii. 1844 9) Find the critical values for a 99% confidence interval using the chi-square distribution

with 6 degrees of freedom. A) 0.297, 13.277 B) 0.412, 16.750

C) 0.872, 16.812

D) 0.676, 18.548

10) The three confidence intervals below were constructed from the same sample. One of

10)

them was computed at a confidence level of 90%, another at a confidence level of 95%, and another at a confidence level of 98%. Which is the confidence level at 98%? A) 16.6 < < 23.4 C) cannot be determined

B) 15.9 < D) 17.1 <

< 24.1 < 22.9

11) A pollster wants to construct a 90% confidence interval for the proportion of adults who

11)

believe that economic conditions are getting better. i. A Gallup poll estimates this proportion to be 0.34. Using this estimate, what sample size is needed so that the confidence interval will have a margin of error of 0.03? ii Estimate the sample size needed if no estimate of p is available. A) i. 1349 B) i. 1655 C) i. 675 D) i. 958 ii. 1503 ii. 1844 ii. 752 ii. 1068 12) A scientist constructs a 98% confidence interval for the mean length of steel rods that are

manufactured by a certain process. She draws a simple random sample of rods and compute the confidence interval. The 98% confidence interval turns out to be 25.1 < < 27.2. She says, "The probability is 95% that the population mean length is between 25.1 and 27.2 centimeters." Is she right? A) Yes B) No

12)

13) A machine used to fill beverage cans is supposed to put exactly 12 ounces of beverage in

13)

each can, but the actual amount varies randomly from can to can. In a sample of 50 cans, the standard deviation of the amount was s = 0.05 ounces. A simple random sample of filled cans will have their volumes measured, and a 95% confidence interval for the mean fill volume will be constructed. Estimate the number of cans that must be sampled for the margin of error to be equal to 0.01 ounces. A) 101 B) 96 C) 100 D) 97 14) A simple random sample of size 20 has mean x = 8.30 and standard deviation s = 5.25.

14)

The population is normally distributed. Construct a 98% confidence interval for the population standard deviation. A) (3.73, 7.96) B) (4.65, 9.50) C) (5.57, 11.03) D) (3.80, 8.28) 15) rScores on the math SAT are normally distributed. A sample of 20 SAT scores had

15)

standard deviation s = 85. i. Construct a 98% confidence interval for the population standard deviation . ii. Someone says that the scoring system for the SAT is designed so that the population standard deviation will be = 100. Does this confidence interval contradict this claim? A) i. (60.45, 128.92) B) i. (61.59, 134.11) ii. Yes ii.Yes C) i. (60.45, 128.92) D) i. (61.59, 134.11) ii. No ii. No 16) Ninteen concrete blocks were sampledand tested for crushing strength in order to

16)

estimate the proportion that were sufficiently strong for a certain application. Fifteen of the 19 blocks were sufficiently strong. Use the small-sample method to construct a 90% confidence interval for the proportion of blocks that are sufficiently strong. A) (0.589, 0.890) B) (0.623, 0.956) C) (0.560, 0.919) D) (0.650, 0.929) 17) A simple random sample of size 16 has mean x = 4.66. The population standard

17)

deviation is = 6.94. Construct a 98% confidence interval for the population mean. A) (-9.47, 18.79) B) (4.66, 8.70) C) (0.62, 8.70) D) (3.13, 6.19) 18) A simple random sample of size 20 has mean x = 10.38 and standard deviation s = 3.39.

The population is normally distributed. Construct a 99% confidence interval for the population standard deviation. A) (2.38, 5.65) B) (5.39, 8.88) C) (2.34, 5.42) D) (8.43, 12.33)

18)

19) A sociologist wants to construct a 98% confidence interval for the proportion of children

19)

aged 8–12 living in New York who own a smartphone. i. A survey by the National Consumers League estimated the nationwide proportion to be 0.64. Using this estimate, what sample size is needed so that the confidence interval will have a margin of error of 0.03? ii. Estimate the sample size needed if no estimate of p is available. A) i. 1386 B) i. 1699 C) i. 693 D) i. 984 ii. 1503 ii. 1844 ii. 752 ii. 1068 20) A sample of size n = 85 has sample mean x = 81 and sample standard deviation s = 5.9.

20)

i. Construct a 95% confidence interval for the population mean . ii. If the confidence level were 99%, would the confidence interval be narrower or wider? A) i. (79.7, 82.3) B) i. (79.3, 82.7) C) i. (79.3, 82.7) D) i. (79.7, 82.3) ii. Wider ii. Wider ii. Narrower ii. Narrower 21) Scores on an IQ test are normally distributed. A sample of 20 IQ scores had standard

21)

deviation s = 6. i. Construct a 99% confidence interval for the population standard deviation . ii. The developer of the test claims that the population standard deviation is = 15. Does this confidence interval contradict this claim? A) i. (4.14, 9.59) B) i. (4.14, 9.59) ii. No ii. Yes C) i. (4.21, 10.00) D) i. (4.21, 10.00) ii. Yes ii. No 22) In a simple random sample of 17 seniors from a certain college, 8 of them had found

22)

jobs. Use the small-sample method to construct a 90% confidence interval for the proportion of seniors at that college who have found jobs. A) (0.297, 0.655) B) (0.291, 0.650) C) (0.257, 0.684) D) (0.263, 0.690) 23) A sample of size n = 61 has mean x = 18.3 and standard deviation s = 2.7.

i. Construct a 90% confidence interval for . ii. Estimate the sample size needed so that a 90% confidence interval for will have a margin of error equal to 0.5. A) i. (18.2, 18.4) B) i. (18.2, 18.4) C) i. (17.7, 18.9) D) i. (17.7, 18.9) ii. 79 ii. 80 ii. 79 ii. 80

23)

24) A sample of size n = 45 has mean x = 10.5 and standard deviation s = 14.3.

i. Construct a 99% confidence interval for . ii. Estimate the sample size needed so that a 99% confidenceinterval for margin of error equal to 2.5. A) i. 4.4 < < 16.6 [Tech:4.5 < < 16.1] ii. 218 B) i. 4.7 < < 16.3 [Tech:4.8 < < 16.2] ii. 218 C) i. 4.7 < < 16.3 [Tech:4.8 < < 16.2] ii. 217 D) i. 4.4 < < 16.6 [Tech:4.5 < < 16.1] ii. 217

24)

will have a

25) A sample of size n = 56 has mean x = 25.2 and standard deviation s = 17.1.

25)

i. Construct a 95% confidence interval for . ii. Estimate the sample size needed so that a 95% confidence interval for will have a margin of error equal to 3.6. A) i. (20.6, 29.8) B) i. (20.9, 29.5) C) i. (20.9, 29.5) D) i. (20.6, 29.8) ii. 87 ii. 87 ii. 89 ii. 89 26) A sample of 42 light bulbs had a mean lifetime of 533 hours. A 95% confidence interval

for the population mean was 525.4 <

26)

< 540.6.

Which one of the following statements is the correct interpretation of the results? A) 95% of the light bulbs in the sample had lifetimes between 525.4 hours and 540.6 hours B) None of these are true. C) The probability that the population mean is between 525.4 hours and 540.6 hours is 0.95. D) We are 95% confident that the mean lifetime of all the bulbs in the population is between 525.4 hours and 540.6 hours. 27) A simple random sample of size 100 has mean x = 8.38. The population standard

27)

deviation is = 4.98. Construct a 98% confidence interval for the population mean. A) (7.22, 9.54) B) (3.40, 13.36) C) (7.86, 8.90) D) (-95.85, 112.61) 28) If we increase the sample size and keep the confidence level the same, we

margin of error. A) decrease

B) increase

the

28)

29) A simple random sample of size 20 has mean x = 3.32. The population standard

29)

deviation is = 1.62. The population is approximately normally distributed. Construct a 90% confidence interval for the population mean. A) (3.32, 3.92) B) (2.72, 3.92) C) (-22.53, 29.17) D) (2.85, 3.79) 30) In a survey of 225 employed adults, 180 said that they had missed one or more days of

30)

work in the past six months. Construct a 98% confidence interval for the proportion of employed adults who missed one or more days of work in the past six months. A) (0.738, 0.862) B) (0.656, 0.944) C) (0.773, 0.827) D) (0.748, 0.852) 31) During an economic downturn, 20 companies were sampled and asked whether they

31)

were planning to increase their workforce. Only 3 of the 20 companies were planning to increase their workforce. Use the small-sample method to construct a 90% confidence interval for the proportion of companies that are planning to increase their workforce. A) (0.030, 0.270) B) (0.072, 0.345) C) (0.046, 0.371) D) (0.007, 0.293) 32) If we increase the confidence level and keep the sample size the same, we

the

32)

33) Six measurements were made of the magnesium ion concentration (in parts per million,

33)

margin of error. A) decrease

B) increase

or ppm) in a city's municipal water supply, with the following results. It is reasonable to assume that the population is approximately normal. 175

177

175

180

138

Construct a 90% confidence interval for the mean magnesium ion concentration. A) (161.2, 166.4) B) (161.0, 166.7) C) (145.7, 182.0) D) (147.3, 180.4) 34) The following MINITAB output presents a confidence interval for a proportion.

Variable x

X N 60 119

Sample p 0.504202

95% CI (0.414369, 0.594035)

Fill in the blanks: We are ________ confident that the population mean is between _______ and _______. A) 95%, 0.428806, 0.579598 B) 97.5%, 0.428806, 0.579598 C) 95%, 0.414369, 0.594035 D) 5%, 0.414369, 0.594035

34)

35) A college admissions officer takes a simple random sample of 70 entering freshmen and

35)

computes their mean mathematics SAT score to be 444. Assume the population standard deviation is = 95. Construct a 98% confidence interval for the mean mathematics SAT score for the entering freshmen class. A) (441, 447) B) (349, 539) C) (418, 470) D) (427, 461) 36) Find the critical values for a 95% confidence interval using the chi-square distribution

with 14 degrees of freedom. A) 5.629, 26.119 B) 5.892, 22.362

C) 6.571, 23.685

36)

D) 5.009, 24.736

37) A random sample of 90 adults is chosen and their mean serum cholesterol level is found

37)

to be 203 milligrams per deciliter. Assume that the population standard deviation is = 44. Based on a 99% confidence interval for the mean serum cholesterol, is it likely that the mean serum cholesterol is greater than 222? (Hint: you should first construct the 99% confidence interval.) A) Yes B) No C) The likelihood cannot be determined. 38) A random sample of 9 TI-89 Titanium calculators being sold over the internet had the

38)

following prices, in dollars. 124 144 147 143 144 136 147 136 150 Assume the population standard deviation is = 27 and that the population is approximately normal. Construct a 90% confidence interval for the mean price for all the TI-89's being sold over the internet. A) (126.4, 156.0) B) (96.8, 185.6) C) (135.7, 146.8) D) (136.8, 145.6) 39) In a small-overlap front crash test, a car is crashed into a simulated telephone pole and

the maximum intrusion of debris into the passenger compartment of a specific model of car is measured. This intrusion is normally distributed with a standard deviation of 3 cm. How many cars must be crashed to establish that a 98% confidence interval for the mean intrusion of debris into the passenger compartment will have a margin of error of 0.3 cm? A) 24 B) 70 C) 542 D) 1 7

39)

40) Use table A.3 from your text to find the critical value ta/2 needed to construct a

confidence interval of the level 95% with the sample size 15. A) 1.753 B) 1.761 C) 2.131

D) 2.145

41) Find the critical value z /2 needed to construct a(n) 80% confidence interval. A) 1.28

B) 2.10

C) 0.84

40)

41)

D) 1.08

42) In a survey of 347 registered voters, 120 of them wished to see Mayor Waffleskate lose

42)

her next election. The Waffleskate campaign claims that no more than 37% of registered voters wish to see her defeated. Does the 90% confidence interval for the proportion support this claim? (Hint: you should first construct the 90% confidence interval for the proportion of registered voters who wish to see Waffleskate defeated.) A) Yes B) No C) The reasonableness of the claim cannot be determined. 43) Measurements were made of the milk fat content (in percent) in six brands of feta cheese

43)

(a variety of goat cheese), with the following results. Assume that the population is normally distributed. 27.4

11.6

16.5

16.1

29.7

11.7

Construct a 95% confidence interval for the population standard deviation . A) (4.90, 19.24) B) (5.05, 17.27) C) (5.27, 16.39) D) (4.61, 15.77) 44) Find the critical value z /2 needed to construct a(n) 98.9% confidence interval. A) 2.54

B) 2.31

C) 2.29

D) 3.32

45) The following MINITAB output presents a 95% confidence interval.

The assumed sigma = 12.0226 Variable N Mean SE Mean x 53 48.921 1.6514

44)

45)

95% CI (45.684, 52.158)

Fill in the blanks: We are ________ confident that the population mean is between _______ and _______. A) 5%, 0, 48.921 B) 5%, 45.684, 52.158 C) 95%, 45.684, 52.158 D) 95%, 0, 48.921 46) Find the standard error for the given values of x and n.

x = 115, n = 182 A) 0.6319

B) 115

C) 0.03575 8

46) D) 0.3681

47) Construct a 95% confidence interval for the population standard deviation

of size 10 has standard deviation s = 16. A) (11.01, 29.21) B) (11.18, 28.08)

C) (11.67, 26.32)

if a sample

D) (10.61, 26.64)

48) Find the critical values for a 98% confidence interval using the chi-square distribution

with 20 degrees of freedom. A) 7.633, 36.191 B) 9.237, 35.020

C) 8.260, 37.566

Mean 89.4928

StDev 33.3397

SE Mean 6.0870

48)

D) 7.434, 39.997

49) The following MINITAB output presents a confidence interval for a population mean.

Variable N x 30

47)

49)

99% CI (72.693, 106.293)

Find the critical value t /2 for a 98% confidence interval. A) 2.462

B) 2.457

C) 2.750

D) 2.760

50) In the confidence interval 22.1 ± 1.8, the quantity 1.8 is called the A) point estimate

B) standard error

C) margin of error

D) critical value

51) A simple random sample of size 61 has mean x = 70.38. The population distribution is

50)

51)

approximately normal, with standard deviation = 16.77. Determine the correct method of finding a 90% confidence interval for the population mean and compute it. A) z-method: (66.85, 73.91) B) z-method: (66.79, 73.97) C) t-method: (66.79, 73.97) D) Cannot compute: the population size is too small. 52) Scores on the math SAT are normally distributed. A sample of 26 SAT scores had a

52)

standard deviation s = 80. Construct a 90% confidence interval for the population standard deviation . A) (68.22, 98.55) B) (65.42, 104.02) C) (64.15, 102.00) D) (65.19, 104.64) 53) Use the given data to construct a confidence interval of the requested level.

x = 80, n = 131, confidence level 95% A) (0.568, 0.653) B) (0.527, 0.694)

C) (0.447, 0.774)

D) (0.541, 0.681)

53)

54) A simple random sample of kitchen toasters is to be taken to determine the mean

54)

operational lifetime in hours. Assume that the lifetimes are normally distributed with population standard deviation = 24 hours. Find the sample size needed so that a 99% confidence interval for the mean lifetime will have a margin of error of 7. A) 212 B) 79 C) 9 D) 4 55) A survey asked 8 adults how many years of education they had. The sample mean was

55)

12.90 with a standard deviation of 3.15. It is reasonable to assume that the population is approximately normal. Construct a 95% confidence interval for the mean number of years of education. A) (-34.0, 34.0) B) (12.0, 13.8) C) (10.3, 15.5) D) (-8.2, 34.0) 56) An Internet service provider sampled 550 customers and found that 55 of them

56)

experienced an interruption in their service during the previous month. The company claims that no more than 10% of customers experienced an interruption in the past month. Does the 98% confidence interval for the proportion support this claim? (Hint: you should first construct the 98% confidence interval for the proportion of customers who experienced an interruption.) A) Yes B) The reasonableness of the claim cannot be determined. C) No 57) The following display from a TI-84 Plus calculator presents a 99% confidence interval

57)

for a proportion.

(0.326914, 0.656692) ^

p = 0.491803 n = 61

Use the information in the display to construct a 95% confidence interval for p. A) (0.375, 0.608) B) (0.366, 0.617) C) (0.387, 0.597) D) (0.327, 0.657) 58) Find the margin of error for the given confidence level and values of x and n.

x = 109, n = 169, confidence level 99% A) 0.09482 B) 0.3550

C) 0.03681

D) 0.6450

58)

59) When constructing a confidence interval for a population mean

from a sample of size 18, the number of degrees of freedom for the critical value t /2 is . A) 9

B) 18

C) 17

D) 19

60) The following MINITAB output presents a 95% confidence interval.

The assumed sigma = 7.7150 Variable N Mean SE Mean x 54 44.669 1.0499

59)

60)

95% CI (42.611, 46.727)

Use the appropriate critical value along with the information in the computer output to construct a 99% confidence interval. A) (42.611, 46.727) B) (43.695, 45.643) C) (41.965, 47.373) D) (42.227, 47.111) 61) Following are the heights in inches of 12 two-year-old apple trees. Assume that the

61)

population is normally distributed. 36.2 37.7 34.7 37.3 42.3 37.0 41.5 38.6 39.5 39.2 42.2 34.7 Construct a 90% confidence interval for the population standard deviation . A) (1.91, 3.84) B) (2.11, 3.72) C) (1.98, 4.10) D) (2.00, 4.01) 62) A single number that estimates the value of an unknown parameter is called a

estimate. A) primary

B) standard

C) critical

D) point

63) The following MINITAB output presents a confidence interval for a proportion.

Variable x

X N 139 178

Sample p 0.780899

95% CI (0.720132, 0.841666)

Use the information in the display to construct a 98% confidence interval for p. A) (0.730, 0.832) B) (0.709, 0.853) C) (0.720, 0.842) D) (0.701, 0.861)

62)

63)

64) Boxes of raisins are labeled as containing 22 ounces. Following are the weights, in

64)

ounces, of a sample of 12 boxes. It is reasonable to assume that the population is approximately normal. 21.90 22.06 21.98 22.13 21.82 22.22 21.99 21.86 22.43 22.34 22.06 22.09 Construct a 90% confidence interval for the mean weight. A) (21.973, 22.174) B) (21.906, 22.240) C) (21.899, 22.248) D) (21.977, 22.170) 65) The following MINITAB output presents a 95% confidence interval.

The assumed sigma = 10.8916 Variable N Mean SE Mean x 38 55.596 1.7669

65)

95% CI (52.133, 59.059)

Find the sample size needed so that the 99% confidence interval will have a margin of error of 1.1. A) 20 B) 531 C) 377 D) 651 66) A researcher wants to construct a 90% confidence interval for the proportion of

66)

elementary school students in Seward County who receive free or reduced-price school lunches. What sample size is needed so that the confidence interval will have a margin of error of 0.08? A) 6 B) 106 C) 65 D) 9 67) The following display from a TI-84 Plus calculator presents a 95% confidence interval.

(52.45, 54.30) x = 53.375 Sx = 3.68 n = 65

Fill in the blanks: We are ________ confident that the population mean is between _______ and _______. A) 95%, 52.45, 54.30 B) 5%, 52.45, 54.30 C) 95%, 0, 53.375 D) 5%, 0, 53.375

67)

68) An Internet service provider sampled 510 customers and found that 65 of them

68)

experienced an interruption in their service during the previous month. Find a point estimate for the population proportion of all customers who experienced an interruption. A) 0.0148 B) 0.1275 C) 0.8725 D) 65 69) Use table A.3 from your text to find the critical value ta/2 needed to construct a

confidence interval of the level 99% with the sample size 22. A) 2.518 B) 2.819 C) 2.831

69)

D) 2.528

70) A sample of 54 tobacco smokers who recently completed a new smoking-cessation

70)

program were asked to rate the effectiveness of the program on a scale of 1 to 10, with 10 corresponding to "completely effective" and 1 corresponding to "completely ineffective". The average rating was 6.3 and the standard deviation was 4.7. Construct a 95% confidence interval for the mean score. A) (5.8, 6.8) B) (5.0, 7.6) C) (0, 6.3)

D) (5.7, 6.9)

71) A sample of size n = 11 is drawn from an approximately normal population whose

standard deviation is interval for . A) (43.90, 49.86)

= 8.5. The sample mean is x = 43.9. Construct a 98% confidence B) (41.86, 45.94)

C) (37.94, 49.86)

D) (35.12, 52.68)

72) Six measurements were made of the magnesium ion concentration (in parts per million,

or ppm) in a city's municipal water supply, with the following results. It is reasonable to assume that the population is approximately normal. 202

164

71)

157

177

113

213

Based on a 98% confidence interval for the mean magnesium ion concentration, is it reasonable to believe that the mean magnesium ion concentration may be greater than 195? (Hint: you should first calculate the 98% confidence interval for the mean magnesium ion concentration.) A) Yes B) The likelihood cannot be determined. C) No

72)

73) A college admissions officer takes a simple random sample of 120 entering freshmen

73)

and computes their mean mathematics SAT score to be 466. Assume the population standard deviation is = 119. Based on a 90% confidence interval for the mean mathematics SAT score, is it likely that the mean mathematics SAT score for entering freshmen class is greater than 487? (Hint: you should first construct the 90% confidence interval for the mean mathematics SAT score.) A) The likelihood cannot be determined. B) Yes C) No 74) Use table A.3 from your text to find the critical value ta/2 needed to construct a

confidence interval of the level 95% with the sample size 2. A) 12.706 B) 6.314 C) 2.920 75) The margin of error is the product of the standard error and the A) critical estimate

B) critical value

C) point estimate

D) standard value

74)

D) 4.303

76) The following display from a TI-84 Plus calculator presents a 99% confidence interval

75)

76)

for a proportion.

(0.288221, 0.619995) ^

p = 0.454108 n = 64

Fill in the blanks: We are ________ confident that the population mean is between _______ and _______. A) 99%, 0, 0.454108 B) 1%, 0, 0.454108 C) 99%, 0.288221, 0.619995 D) 1%, 0.288221, 0.619995 77) When the number of degrees of freedom is large, the Student’s t distribution is close to

the A) ideal

distribution. B) normal

C) uniform

D) binomial

77)

78) The following MINITAB output presents a confidence interval for a population mean.

Variable N Mean x 79 133.2032

StDev 27.4052

SE Mean 3.0833

How many degrees of freedom are there? A) 80 B) 79

C) 78

99% CI (125.062, 141.344)

D) 3.0833

79) A sample of size n = 45 is drawn from a population whose standard deviation is

Find the margin of error for a 98% confidence interval for . A) 1.25 B) 4.33 C) 1.23

= 12.5.

79)

D) 1.86

80) A sample of size n = 17 is drawn from a normal population. Find the critical value t /2

needed to construct a 99% confidence interval. A) 2.576 B) 2.898 C) 2.921

78)

80)

D) 2.584

81) In a survey of 306 registered voters, 132 of them wished to see Mayor Waffleskate lose

81)

her next election. Construct a 90% confidence interval for the proportion of registered voter who want to see Mayor Waffleskate defeated. A) (0.385, 0.478) B) (0.403, 0.460) C) (0.395, 0.468) D) (0.355, 0.508) 82) Use table A.3 from your text to find the critical value ta/2 needed to construct a

confidence interval of the level 90% with the sample size 63. A) 1.671 B) 1.292 C) 1.664

D) 1.296

83) Find the confidence level for an interval which has a critical value of 1.85. A) 6.43%

B) 93.57%

C) 96.78%

C) 2.189

84)

D) 2.508

85) A sample of size n = 11 has a sample mean x = 11.6 and sample standard deviation

s = 2.7. It is reasonable to assume that the population is approximately normal. Construct a 90% confidence interval for the population mean . A) (10.7, 12.5) B) (10.5, 12.7) C) (11.2, 12.0) D) (10.1, 13.1)

83)

D) 3.22%

84) Find the critical value t /2 needed to construct a confidence interval of the given level

with the given sample size. Level 98%, sample size 22 A) 2.518 B) 2.326

82)

85)

86) A simple random sample of size 51 has mean x = 71.06 and standard deviation s = 16.77.

86)

The population distribution is unknown. Determine the correct method of finding a 95% confidence interval for the population mean and compute it. A) z-method: (66.46, 75.66) B) Cannot compute: the population size is too small. C) z-method: (66.34, 75.78) D) t-method: (66.34, 75.78) 87) A random sample of a specific brand of snack bar is tested for calorie count, with the

87)

following results: 140 145 141 153 150 155 154 155 148 Assume the population standard deviation is = 21 and that the population is approximately normal. Construct a 90% confidence interval for the calorie count of the snack bars. A) (144.7, 153.3) B) (137.5, 160.5) C) (114.5, 183.5) D) (145.8, 152.2) 88) A researcher wants to construct a 98% confidence interval for the proportion of

88)

elementary school students in Seward County who receive free or reduced-price school lunches. A state-wide survey indicates that the proportion is 0.60. Using this estimate, what sample size is needed so that the confidence interval will have a margin of error of 0.07? A) 189 B) 265 C) 19 D) 8 89) In a sample of 16 children, the mean age at which they first began to combine words was

89)

16.54 months, with a standard deviation of 5.32 months. It is reasonable to assume that the population is approximately normal. Construct a 95% confidence interval for the mean age at which children first begin to combine words. A) (15.8, 17.2) B) (-28.8, 61.9) C) (16.2, 16.8) D) (13.7, 19.4) 90) A simple random sample of size 22 has mean x = 70.38 and standard deviation s = 16.12.

The population distribution is unknown. Determine the correct method of finding a 95% confidence interval for the population mean and compute it. A) Cannot compute: the population size is too small. B) z-method: (63.64, 77.12) C) t-method: (63.23, 77.53) D) z-method: (63.23, 77.53)

90)

91) The following display from a TI-84 Plus calculator presents a 95% confidence interval.

91)

(51.044, 61.674) x = 56.359 n = 63

Fill in the blanks: We are ________ confident that the population mean is between _______ and _______. A) 95%, 51.044, 61.674 B) 5%, 0, 56.359 C) 95%, 0, 56.359 D) 5%, 51.044, 61.674 92) The following MINITAB output presents a confidence interval for a population mean.

Variable N Mean x 25 114.4715

StDev 30.2017

SE Mean 6.0403

92)

99% CI (97.577, 131.366)

Use the information in the output to construct a 98% confidence interval. A) (111.732, 117.211) B) (111.397, 117.546) C) (97.577, 131.366) D) (99.419, 129.524) 93) Scientists want to estimate the mean weight gain of mice after they have been fed a

93)

special diet. From previous studies, it is known that the weight gain is normally distributed with standard deviation 3.5 grams. How many mice must be weighed so that a 98% confidence interval for mean weight will have a margin of error of 0.3 grams? A) 737 B) 1 C) 95 D) 28 94) Find the point estimate for the given values of x and n.

x = 124, n = 209 A) 0.4067

B) 0.5933

C) 0.03398

94) D) 124

95) An Internet service provider sampled 540 customers and found that 90 of them

experienced an interruption in their service during the previous month. Construct a 99% confidence interval for the proportion of all customers who have experienced a service interruption. A) (0.167, 0.833) B) (0.792, 0.875) C) (0.129, 0.204) D) (0.125, 0.208)

95)

96) In a survey of 354 registered voters, 157 of them wished to see Mayor Waffleskate lose

96)

her next election. Find a point estimate for the proportion of registered voters who wish to see Mayor Waffleskate defeated. A) 0.02640 B) 157 C) 0.4435 D) 0.5565 97) A random sample of electronic components had the following operational times before

97)

failure, in hours. 349 345 338 353 337 341 359 343 337 Assume the population standard deviation is = 31 and that the population is approximately normal. Construct a 95% confidence interval for the operational time before failure. A) (339.6, 349.7) B) (337.1, 352.3) C) (324.4, 364.9) D) (283.9, 405.4) 98) A random sample of 60 adults is chosen and their mean serum cholesterol level is found

98)

to be 198 milligrams per deciliter. Assuming that the population standard deviation is = 41, compute a 90% confidence interval for the mean serum cholesterol level for adults. A) (183, 213) B) (189, 207) C) (197, 199) D) (157, 239) TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 99) The Student’s t curve is less spread out than the standard normal curve. 100) The Student’s t distribution should not be used to find a confidence interval for

99)

100)

outliers are present in a small sample. 101) If a 98% confidence interval for a population mean is 1.6 <

is 0.98 that

< 2.4, then the probability

101)

is between 1.6 and 2.4.

102) To construct a confidence interval for a population mean, we add and subtract the critical

value from the point estimate.

102)

Answer Key Testname: C8

1) B 2) B 3) A 4) D 5) C 6) D 7) C 8) A 9) D 10) B 11) C 12) B 13) D 14) D 15) D 16) A 17) C 18) A 19) A 20) A 21) C 22) A 23) C 24) B 25) A 26) D 27) A 28) A 29) B 30) A 31) B 32) B 33) D 34) C 35) C 36) A 37) B 38) A 39) C 40) D 41) A 42) A 43) A 44) A 45) C 46) C 47) A 48) C 49) A 50) C 19

Answer Key Testname: C8

51) A 52) D 53) B 54) B 55) C 56) C 57) B 58) A 59) C 60) C 61) C 62) D 63) B 64) D 65) D 66) B 67) A 68) B 69) C 70) B 71) C 72) A 73) C 74) A 75) B 76) C 77) B 78) C 79) B 80) C 81) A 82) A 83) B 84) A 85) D 86) D 87) B 88) B 89) D 90) A 91) A 92) D 93) A 94) B 95) D 96) C 97) C 98) B 99) FALSE 100) TRUE 20

Answer Key Testname: C8

101) FALSE 102) FALSE

Exam Name___________________________________

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) The General Social Survey asked a large number of people how much time they spent

watching TV each day. The mean number of hours was 3.17 with a standard deviation of 2.85. Assume that in a sample of 40 teenagers, the sample standard deviation of daily TV time is 2.4 hours, and that the population of TV watching times is normally distributed. Can you conclude that the population standard deviation of TV watching times for teenagers is less than 2.85? Use the = 0.01 level of significance. A) Reject H 0 . B) Do not reject H 0 . 2) Charlie will perform a hypothesis test at the

= 0.05 level. Felice will perform the same

test at the = 0.01 level. i. If H 0 is true, who has a greater probability of making a Type I error? ii. If H 0 is false, who has a greater probability of making a Type II error? A) i. Charlie

B) i. Felice

ii. Felice

ii. Charlie

3) Water pipe to be used in a certain application is required to have a mean breaking

strength of more than 2500 pounds per foot. A test is made of H 0 : = 2500 versus H 1: > 2500. There are two possible errors: i. The true mean is greater than 2500, but the pipe is not used. ii. The true mean is 2500 or less, but the pipe is used. Which is a Type I error? A) ii

B) i

4) A hypothesis test is performed at a significance level

a Type I error? A) 0.99

B) 0.01

= 0.01. What is the probability of

C) 0.005

D) 0.995

5) Last year, the mean amount spent by customers at a certain restaurant was $37. The

restaurant owner believes that the mean may be higher this year. State the appropriate null and alternate hypotheses. A) H 0 : > 37, H 1 : = 37 B) H 0 : < 37, H 1 : > 37 C) H 0 :

D) H 0 :

= 37, H 1: > 37

= 37, H 1:

6) A test was made of the hypotheses H 0:

= 15 versus H 1 : > 15. Four statisticians wrote

summaries of the results. For each summary, state whether it contains enough information. If there is not enough information, indicate what needs to be added. Because P < 0.05, we reject H 0 at the = 0.05 level. A) Enough information

B) State P-value

7) Scores on an IQ test are normally distributed.A sample of 25 IQ scores had standard

deviation s = 8.5. The developer of the test claims that the population standard deviation is = 12. Do these data provide sufficient evidence to contradict this claim? Use the = 0.05 level of significance. A) Do not reject H 0 . B) Reject H 0 . 8) In a recent year, the mean weight of newborn boys in a certain country was 6.2 pounds.

A doctor wants to know whether the mean weight of newborn girls differs from this. State the appropriate null and alternate hypotheses. 6.2 A) H 0 : = 6.2, H 1 : > 6.2 B) H 0 : = 6.2, H 1 : C) H 0 :

= 6.2, H 1:

9) When testing H 0 :

= 0 versus H 1 : contain 0 , we reject H 0 at the A) 0.98

D) H 0 :

< 6.2

< 6.2, H 1:

= 6.2

> 0 , if a 98% confidence interval does not level.

B) 0.02

C) 0.01

D) 0.99

10) A certain model of car can be ordered with either a large or small engine. The mean

10)

number of miles per gallon for cars with a small engine is 24.1. An automotive engineer thinks that the mean for cars with the larger engine will be less than this. State the appropriate null and alternate hypotheses. 24.1, H 1 : = 24.1 A) H 0 : B) H 0 : < 24.1, H 1: > 24.1 C) H 0 :

D) H 0 :

= 24.1, H 1: < 24.1

= 24.1, H 1:

24.1

11) A 95% confidence interval for

is computed to be (1.75, 3.25). For the following hypotheses, state whether H 0 will be rejected at the 0.05 level. H 0: = 4 versus H 1 :

A) No

B) Yes

12) To test a hypothesis about a standard deviation using a sample of size 18, we use a

chi-square distribution with A) 16

11)

degrees of freedom.

B) 19

C) 17

D) 18

12)

13) A test was made of the hypotheses H 0:

= 15 versus H 1 : > 15. Four statisticians wrote

13)

summaries of the results. For each summary, state whether it contains enough information. If there is not enough information, indicate what needs to be added. The P-value was 0.02, so we reject H 0 at the = 0.05 level. A) State value of test statistic

B) Enough information

14) A sample of 22 one-year-old girls had a mean weight of 24.1 pounds with a standard

14)

deviation of 4.3 pounds. Assume that the population of weights is normally distributed. A pediatrician claims that the standard deviation of the weights of one-year-old girls is less than 5.7 pounds. Do the data provide convincing evidence that the pediatrician’s claim is true? Use the = 0.10 level of significance. A) Reject H 0 . B) Do not reject H 0 . 15) Batteries used in a certain heart pacemaker have a mean life of 16 years. A new type of

15)

battery is being tested and will be used in place of the old battery if it can be shown to have a mean lifetime of more than 16 years. A test is made of H 0: = 16 versus H 1:

> 16. There are two possible errors:

i. The true mean is 16 or less, but the new batteries are used. ii. The true mean is greater than 16, but the new batteries are not used. Which is a Type II error? A) ii

B) i

16) A simple random sample of size 13 has mean x = 7.32 and standard deviation s = 2.46.

The population is approximately normally distributed. i. State which type of parameter is to be tested. ii. Can you conclude that the population mean differs from 7? Use the = 0.01 level of significance. A) i. Mean ii. Reject H 0 .

B) i. Standard deviation

ii. Do not reject H 0.

C) i. Mean

D) i. Standard deviation

ii. Do not reject H 0.

ii. Reject H 0 .

16)

17) A simple random sample of size 16 has mean x = 3.7 and standard deviation s = 6.3. The

17)

population is normally distributed. i. State which type of parameter is to be tested. ii. Can you conclude that the population standard deviation is greater than 5.5? Use the = 0.05 level of significance. A) i. Mean ii. Reject H 0 .

B) i. Mean

ii. Do not reject H 0.

C) i. Standard deviation

D) i. Standard deviation

ii. Do not reject H 0.

ii. Reject H 0 .

18) Water pipe to be used in a certain application is required to have a mean breaking

18)

strength of more than 2200 pounds per foot. A test is made of H 0 : = 2200 versus H 1: > 2200. There are two possible errors: i. The true mean is greater than 2200, but the pipe is not used. ii. The true mean is 2200 or less, but the pipe is used. Which is a Type II error? A) i

B) ii

19) In a simple random sample of 120 law students, 50 were women. Can you conclude that

19)

less than half of law students are women? Use the = 0.01 level of significance. A) i. Standard deviation B) i. Proportion ii. Do not reject H 0. ii. Reject H 0 . C) i. Proportion

D) i. Standard deviation

ii. Do not reject H 0. 20) A test was made of the hypotheses H 0:

ii. Reject H 0 . = 15 versus H 1 : > 15. Four statisticians wrote

20)

summaries of the results. For each summary, state whether it contains enough information. If there is not enough information, indicate what needs to be added. The critical value was 1.645. Because t = 2.05, we reject H 0 at the = 0.05 level. A) State P-value

B) Enough information

21) Scores on the math SAT are normally distributed. A sample of 20 SAT scores had

standard deviation s = 72. Someone says that the scoring system for the SAT is designed so that the population standard deviation will be = 100. Do these data provide sufficient evidence to contradict this claim? Use the = 0.05 level of significance. A) Reject H 0 . B) Do not reject H 0 .

21)

22) A test was made of the hypotheses H 0:

= 15 versus H 1 : > 15. Four statisticians wrote

22)

summaries of the results. For each summary, state whether it contains enough information. If there is not enough information, indicate what needs to be added. The critical value was 1.645. Because t > 1.645, we reject H 0 at the = 0.05 level. A) State value of test statistic 23) You want to test H 0 :

= 4 versus H 1 :

for . The 95% confidence interval is 5.1 <

B) Enough information

4, so you compute a 95% confidence interval < 8.0. Do you reject H 0 at the

level? A) No

= 0.05

B) Yes

24) A simple random sample of size 65 has mean x = 57.6. The population standard

deviation is

23)

24)

= 12.8.

i. State which type of parameter is to be tested. ii. Can you conclude that the population mean is less than 60? Use the = 0.05 level of significance. A) i. Mean ii. Do not reject H 0.

B) i. Standard deviation

ii. Do not reject H 0.

C) i. Standard deviation

D) i. Mean

ii. Reject H 0 .

25) Batteries used in a certain heart pacemaker have a mean life of 20 years. A new type of

battery is being tested and will be used in place of the old battery if it can be shown to have a mean lifetime of more than 20 years. A test is made of H 0 : = 20 versus H 1 : > 20. There are two possible errors: i. The true mean is 20 or less, but the new batteries are used. ii. The true mean is greater than 20, but the new batteries are not used. Which is a Type I error? A) i

B) ii

25)

26) A Gallup poll sampled 1000 adults in the United States. Of these people, 840 said they

enjoyed situations in which they competed with other people. Can you conclude that less than 75% of U.S. adults like to compete? Use the critical value method with significance level = 0.05. i. State the null and alternate hypotheses. ii. Compute the test statistic. iii. Find the critical value. A) i. H 0 : p = 0.75, H 1: p < 0.75 B) i. H 0 : p = 0.8, H 1 : p > 0.8 ii. 6.57 iii. -1.645 C) i. H 0 : p = 0.75, H 1: p < 0.75

ii. 7.03 iii. 1.645 D) i. H 0 : p = 0.8, H 1 : p > 0.8

ii. 7.03 iii. -1.645

ii. 6.57 iii. 1.645

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. 27) In a simple random sample of size 100, there were 60 individuals in the category

27)

of interest. It is desired to test H 0 : p = 0.69 versus H 1 : p < 0.69. ^ i). Compute the sample proportion p.

ii). It is desired to test H 0 : p = 0.69 versus H 1 : p > 0.69 Compute the test statistic z. iii). Do you reject H 0 at the 0.05 level?

28) A sample of 49 students enroll in a program that claims to improve scores on the

quantitative reasoning portion of the Graduate Record Examination (GRE). The participants take a mock GRE test before the program begins and again at the end to measure their improvement. The mean number of points improved was x = 20. Assume the standard deviation is = 44 and let be the population mean number of points improved. To determine whether the program is effective, a test is made of the hypotheses H 0: = 0 versus H 1 : > 0. i). Compute the value of the test statistic. ii). Compute the P-value. iii). Do you reject H 0 at the = 0.05 level?

28)

26)

29) At a certain university, 15% of students fail general chemistry on their first

29)

attempt. Professor Brown teaches at this university and believes that the rate of first-time failure in his general chemistry classes is 24%. He samples 75 students from last semester who were first-time enrollees in general chemistry and finds that 11 of them failed his course. i). State the appropriate null and alternate hypotheses. ii). Compute the test statistic z. iii). Using = 0.05, can you conclude that the percentage of failures differs from 24%?

30) At a water bottling facility, a technician is testing a bottle filling machine that is

30)

supposed to deliver 500 milliliters of water. The technician dispenses 45 samples of water and determines the volume of each sample. The 45 samples have a mean volume of x = 497.9 mL. The machine is out of calibration if the mean volume differs from 500 mL. The technician wants to perform a hypothesis test to determine whether the machine is out of calibration. The standard deviation of the dispensed volume is known to be = 4.4. i). State the appropriate null and alternate hypotheses. ii). Compute the value of the test statistic. iii). State a conclusion. Use the = 0.01 level of significance. 31) Thirty-seven members of a bowling league sign up for a program that claims to

improve bowling scores. The participants bowl a set of five games before the program begins and a set of five games again at the end to measure their improvement. The mean number of points improved (over the set of five games) was x = 18. Assume the standard deviation is = 51 and let be the population mean number of points improved for the set of five games. To determine whether the program is effective, a test is made of the hypotheses H 0: = 0 versus H 1 : > 0. i). Compute the value of the test statistic. ii). Compute the P-value. iii). Do you reject H 0 at the = 0.05 level?

31)

32) The mean annual tuition and fees for a sample of 14 private colleges was $35,400

32)

with a standard deviation of $4700. A dotplot shows that it is reasonable to assume that the population is approximately normal. You wish to test whether the mean tuition and fees for private colleges is different from $31,400. i). State the null and alternate hypotheses. ii). Compute the value of the test statistic and state the number of degrees of freedom. iii). State a conclusion regarding H 0. Use the = 0.01 level of significance. 33) The Golden Comet is a hybrid chicken that is prized for its high egg production

33)

rate and gentle disposition. According to recent studies, the mean rate of egg production for 1-year-old Golden Comets is 4.7 eggs/week. Sarah has 37 1-year-old hens that are fed exclusively on natural scratch feed: insects, seeds, and plants that the hens obtain as they range freely around the farm. Her hens exhibit a mean egg-laying rate of 6.5 eggs/day. Sarah wants to determine whether the mean laying rate for her hens is higher than the mean rate for all Golden Comets. Assume the population standard deviation to be = 2.7 eggs/day. i. State the appropriate null and alternate hypotheses. ii. Compute the value of the test statistic. iii. State a conclusion. Use the = 0.01 level of significance. 34) A market research firm reported that the mean annual earnings of all family

practitioners in the United States was $177,156. A random sample of 36 family practitioners in New York that month had mean earnings of x = $216,558 with a standard deviation of $35,551. You wish to test whether family practitioners in New York make more than the national average. i). State the null and alternate hypotheses. ii). Compute the value of the test statistic and state the number of degrees of freedom. iii). State a conclusion regarding H 0. Use the = 0.1 level of significance.

34)

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 35) Mercury is a heavy metal that can cause severe health problems in even small

35)

concentrations. Fish and shellfish efficiently concentrate mercury into their flesh, so it is important to monitor seafood for its mercury content. An extensive study conducted in 1980 concluded that the mean mercury level in oysters from the White Bear estuary was 0.017 parts per million (ppm) with a standard deviation = 0.033 ppm. In 2012, a sample of 40 oysters from the same estuary exhibited a mean mercury concentration of 0.007 ppm. Can you conclude that the 2012 mercury concentration is lower than in 1980? Use the = 0.05 level of significance. A) No. There is insufficient evidence to conclude that the mercury concentration has decreased from 1980 to 2012. B) Yes. The mercury concentration appears to be lower in 2012. C) There is not enough information to reach a conclusion. 36) The following display from a TI-84 Plus calculator presents the results of a hypothesis

test.

49 z = -0.774667 p = 1.561464 x = 47.34 n = 49

What is the value of the test statistic? A) 1.561464 B) 49

C) 47.34

D) -0.774667

36)

37) A psychologist is designing an experiment in which rats will navigate a maze. Ten rats

37)

run the maze, and the time it takes for each to complete the maze is recorded. The results are as follows: 69.0 62.2

66.3 63.9

42.8 68.7

67.9 66.7

62.0 51.6

Following is a boxplot for the data. Is it reasonable to assume the conditions for performing a hypothesis test are satisfied?

A) Yes

B) No

38) The following output from MINITAB presents the results of a hypothesis test.

38)

Test of mu = 33 vs. not = 33 The assumed standard deviation 14.3 N 52

Mean 30.56

SE Mean 2.581707

Do you reject H 0 at the

95% CI (25.4998537, 35.6201463)

Z -1.230426

P 0.218538

= 0.01 level?

A) Yes B) No C) There is not enough information to draw a conclusion. 39) A tire company claims that the lifetimes of its tires average 50,000 miles. The standard

deviation of tire lifetimes is known to be = 5000 miles. You sample 100 tires and will test the hypothesis H 0 : = 50,000 versus H 1 : < 50,000 at the = 0.05 level of significance. Find the power of the test against the alternative 1 = 48,500 A) 0.7420 B) 0.4772 C) 1.645

D) 0.9131

39)

40) A test of H 0 :

= 43 versus H 1:

43 is performed using a significance level of

40)

= 0.05. The P-value is 0.122. If the true value of is 43, does the conclusion result in a Type I error, a Type II error, or a correct decision? A) Correct decision B) Type II error C) Type I error 41) A test of H 0 :

= 45 versus H 1: < 45 is performed using a significance level of

41)

= 0.05. The P-value is 0.115. If the true value of is 43, does the conclusion result in a Type I error, a Type II error, or a correct decision? A) Correct decision B) Type II error C) Type I error 42) When results are statistically significant, they do not necessarily have

significance. A) emperical

B) theoretical

C) practical

42) D) mathematical

43) The Golden Comet is a hybrid chicken that is prized for its high egg production rate and

43)

gentle disposition. According to recent studies, the mean rate of egg production for 1-year-old Golden Comets is 5.7 eggs/week. Sarah has 37 1-year-old hens that are fed exclusively on natural scratch feed: insects, seeds, and plants that the hens obtain as they range freely around the farm. Her hens exhibit a mean egg-laying rate of 5.9 eggs/day. Sarah wants to determine whether the mean laying rate for her hens is higher than the mean rate for all Golden Comets. Assume the population standard deviation to be = 1.5 eggs/day. Compute the value of the test statistic. A) 0.13 B) 0.81 C) 0.99 D) 0.79 44) Historically, a certain region has experienced 97 thunder days annually. (A "thunder day"

is day on which at least one instance of thunder is audible to a normal human ear). Over the past six years, the mean number of thunder days is 73 with a standard deviation of 29. Can you conclude that the mean number of thunder days is less than 97? Use the = 0.10 level of significance and assume the population is approximately normal. A) There is not enough information to draw a conclusion. B) Yes. The number of thunder days appears to be less than 97. C) No. There is insufficient evidence to conclude that the number of thunder days is less than 97.

44)

45) A grocery store owner claims that the mean amount spent per checkout is more than $67.

45)

A test is made of H 0: = 67 versus H 1 : > 67. The null hypothesis is rejected. State the appropriate conclusion. A) There is not enough evidence to conclude that the mean checkout price is greater than $67. B) The mean checkout amount is less than or equal to $67. C) The mean checkout amount is greater than $67. D) There is not enough evidence to conclude that the mean checkout price is less than or equal to $67. 46) A market research firm reported that the mean annual earnings of all family practitioners

46)

in the United States was $178,011. A random sample of 55 family practitioners in New York that month had mean earnings of x = $197,685 with a standard deviation of $35,405. You wish to test whether family practitioners in New York make more than the national average. Compute the value of the test statistic and state the number of degrees of freedom. A) 0.010; 55 degrees of freedom B) 0.010; 54 degrees of freedom C) 4.121; 55 degrees of freedom D) 4.121; 54 degrees of freedom 47) Forty-nine members of a bowling league sign up for a program that claims to improve

bowling scores. The participants bowl a set of five games before the program begins and a set of five games again at the end to measure their improvement. The mean number of points improved (over the set of five games) was x = 21. Assume the standard deviation is = 57 and let be the population mean number of points improved for the set of five games. To determine whether the program is effective, a test is made of the hypotheses H 0 : = 0 versus H 1 : > 0. Compute the P-value. A) 2.5789

B) 0.0013

C) 0.0025

D) 0.0050

47)

48) A sample of 48 students enroll in a program that claims to improve scores on the

48)

quantitative reasoning portion of the Graduate Record Examination (GRE). The participants take a mock GRE test before the program begins and again at the end to measure their improvement. The mean number of points improved was x = 5. Assume the standard deviation is = 42 and let be the population mean number of points improved. To determine whether the program is effective, a test is made of the hypotheses H 0 : = 0 versus H 1: > 0. Compute the P-value. A) 0.1024

B) 0.0512

C) 0.2047

D) 0.8248

49) Forty-seven members of a bowling league sign up for a program that claims to improve

49)

bowling scores. The participants bowl a set of five games before the program begins and a set of five games again at the end to measure their improvement. The mean number of points improved (over the set of five games) was x = 16. Assume the standard deviation is = 43 and let be the population mean number of points improved for the set of five games. To determine whether the program is effective, a test is made of the hypotheses H 0 : = 0 versus H 1 : > 0. Using technology, compute the P-value. A) 0.0027 B) 0.0054

C) 0.0013

D) 2.5509

50) A poll of 1275 adults in the United States asked how much confidence they had in banks.

50)

A total of 217 adults said they had a great deal of confidence. An economist claims that less than 15% of U.S. adults have a great deal of confidence in banks. Can you conclude that the economist's claim is true? Use the = 0.01 level of significance. A) Yes B) No C) No conclusion is possible. 51) A random sample of size 14 from a normal distribution has standard deviation s = 64.

Test H 0: = 48 versus H 1 : > 48. Use the

= 0.05 level of significance.

A) Reject H 0 .

B) Do not reject H 0 .

51)

52) The following display from a TI-84 Plus calculator presents the results of a hypothesis

52)

test for a population proportion p.

prop > 0.17 z = 1.72 p = 0.042716 ^

p = 0.237 n = 93

Can H 0 be rejected at the 0.01 level? A) No

B) Yes

53) Following are outstanding credit card balances for a sample of 16 college seniors at a

53)

large university. 683 2640

153 597

748 746

781 603

1024 1227

768 649

463 723

535 590

The dotplot of this data is below. Is it reasonable to assume that the conditions for performing a hypothesis test are satisfied?

A) Yes

B) No

54) Find the critical value for the following values of the significance level , sample size n,

54)

and alternate hypothesis H 1 . = 0.01, n = 6, H 1 : < 0 A) -2.326 B) -4.032

C) -3.143

D) -3.365

55) A sample of 65 chewable vitamin tablets have a sample mean of 237 milligrams of

vitamin C. Nutritionists want to perform a hypothesis test to determine how strong the evidence is that the mean mass of vitamin C per tablet differs from 240 milligrams. State the appropriate null and alternate hypotheses. 237 240 A) H 0 : = 237, H 1 : B) H 0 : = 240, H 1 : C) H 0 :

D) H 0 :

240, H 1 : = 240

237, H 1 : = 237

55)

56) The mean annual tuition and fees for a sample of 11 private colleges was $34,300 with a

56)

standard deviation of $6400. A dotplot shows that it is reasonable to assume that the population is approximately normal. You wish to test whether the mean tuition and fees for private colleges is different from $31,800. State the null and alternate hypotheses. 31,800 A) H 0 : = 31,800, H 1 : C) H 0 :

31,800, H 1 : = 31,800

B) H 0 :

= 31,800, H 1: = 34,300

D) H 0 :

= 34,300, H 1:

34,300

57) At a water bottling facility, a technician is testing a bottle filling machine that is

57)

supposed to deliver 1000 milliliters of water. The technician dispenses 43 samples of water and determines the volume of each sample. The 43 samples have a mean volume of x = 1001.0 mL. The machine is out of calibration if the mean volume differs from 1000 mL. The technician wants to perform a hypothesis test to determine whether the machine is out of calibration. State the appropriate null and alternate hypotheses. 1000 1001.0, H 1 : = 1001.0 A) H 0 : = 1000, H 1 : B) H 0 : C) H 0 :

D) H 0 :

= 1000, H 1: < 1000

= 1001.0, H 1: > 1001.0

58) A test has power 0.80 when 1 = 11. True or false: the probability of rejecting

H 0 when 1 = 11 is 0.80. A) False 59) A test of H 0 :

58)

B) True

= 57 versus H 1: < 57 is performed using a significance level of

= 0.05. The P-value is 0.009. If the true value of is 57, does the conclusion result in a Type I error, a Type II error, or a correct decision? A) Correct decision B) Type I error C) Type II error

59)

60) The following display from a TI-84 Plus calculator presents the results of a hypothesis

60)

test for a population mean .

< 52 t = -1.001800 p = 0.160136 x = 51.84 Sx = 1.27770 n = 64

What is the value of s? A) 0.160136 61) A test of H 0 :

B) 51.84

= 67 versus H 1:

C) 1.27770

D) -1.001800

67 is performed using a significance level of

61)

= 0.01. The value of the test statistic is z = -2.40. Is H 0 rejected? A) No B) Yes C) It cannot be determined. 62) Scores on an IQ test are normally distributed. A sample of 20 IQ scores had standard

deviation s = 8. The developer of the test claims that the population standard deviation is = 12. Do these data provide sufficient evidence to contradict this claim? Use the = 0.05 level of significance. A) Do not reject H 0 . There is insufficient evidence to conclude that the population standard deviation differs from 12. B) Reject H 0 .

The population standard deviation appears to differ from 12.

62)

63) A fleet of rental cars - all the same make, model, and year - has a mean fuel efficiency of

63)

27.7 miles per gallon (mpg). A random sample of 59 cars are selected and the air filter of each is replaced with a new one. Let be the population mean fuel efficiency score that would occur if every car's air filter were replaced. The air filter change is deemed effective if > 27.7 mpg. A test is made of H 0 : = 27.7 versus H 1 : > 27.7 . Consider these possible conclusions: i). The air filter changes are effective. ii). The air filter changes are not effective. iii). The air filter changes might not be effective. Which of the three conclusions is best if H 0 is not rejected? A) i

B) iii

C) ii

64) The following output from MINITAB presents the results of a hypothesis test for a

64)

population mean . Test of mu = 49 vs. not = 49 N 35

Mean 45.32

StDev 25.802554

What is the value of s? A) 9.7

SE Mean 4.361428

95% CI T (36.456524, 54.183476) -0.843760

B) 0.404701

C) 4.361428

P 0.404701

D) 25.802554

65) Forty-seven members of a bowling league sign up for a program that claims to improve

bowling scores. The participants bowl a set of five games before the program begins and a set of five games again at the end to measure their improvement. The mean number of points improved (over the set of five games) was x = 10. Assume the standard deviation is = 46 and let be the population mean number of points improved for the set of five games. To determine whether the program is effective, a test is made of the hypotheses H 0 : = 0 versus H 1 : > 0. Do you reject H 0 at the

= 0.05 level?

A) Yes B) There is not enough information to draw a conclusion. C) No

65)

66) The mean annual tuition and fees for a sample of 13 private colleges was $28,000 with a

66)

standard deviation of $5700. A dotplot shows that it is reasonable to assume that the population is approximately normal. You wish to test whether the mean tuition and fees for private colleges is different from $31,800. Compute the value of the test statistic and state the number of degrees of freedom. A) -0.667; 12 degrees of freedom B) -2.404; 13 degrees of freedom C) -2.404; 12 degrees of freedom D) -0.667; 13 degrees of freedom 67) Use technology to find the P-value for the following values of the test statistic t, sample

67)

size n, and alternate hypothesis H 1 . t = 2.009, n = 7, H 1 : > 0 A) 0.0456 B) 0.0912

C) 0.0844

D) 0.0422

68) A machine that fills beverage cans is supposed to put 20 ounces of beverage in each can.

68)

Following are the amounts measured in a simple random sample of eight cans. 20.01 19.95 19.98 19.99 20.05 20.14 20.09 20.13 Assume that the sample is approximately normal. Can you conclude that the mean volume differs from 20 ounces? Use the = 0.1 level of significance. A) There is not enough information to draw a conclusion. B) Yes. The mean fill volume appears to differ from 20 ounces. C) No. There is insufficient evidence to conclude that the mean fill volume differs from 20 ounces. 69) Thirty-five members of a bowling league sign up for a program that claims to improve

bowling scores. The participants bowl a set of five games before the program begins and a set of five games again at the end to measure their improvement. The mean number of points improved (over the set of five games) was x = 12 . Assume the standard deviation is = 59 and let be the population mean number of points improved for the set of five games. To determine whether the program is effective, a test is made of the hypotheses H 0 : = 0 versus H 1 : > 0. Compute the value of the test statistic. A) 0.20 B) 0.1151

C) 1.20

D) 9.24

69)

70) The following output from MINITAB presents the results of a hypothesis test.

70)

Test of mu = 37 vs. not = 37 The assumed standard deviation 7.5 N 39

Mean 39.21

SE Mean 0.355947

95% CI (5.58096794, 6.97628188)

What are the null and alternate hypotheses? 37, H 1 : = 37 A) H 0 : C) H 0 :

= 39.21, H 1:

39.21

Z 1.840193

B) H 0 :

= 37, H 1: = 39.21

D) H 0 :

= 37, H 1:

P 0.065740

71) In a survey of 416 cigarette smokers, 27 of them reported that they have tried hypnosis

71)

therapy to try to quit smoking. Can you conclude that less than one-tenth of smokers have tried hypnosis therapy? Use the = 0.01 level of significance. A) Yes B) No C) No conclusion is possible. 72) The following output from MINITAB presents the results of a hypothesis test for a

72)

population mean . Test of mu = 32 vs. not = 32 N 54

Mean 34.71

StDev 10.859387

SE Mean 1.477775

95% CI (31.745937, 37.674063)

How many degrees of freedom are there? A) 53 B) 55

C) 32

T 1.833838

P 0.072295

D) 54

73) If P = 0.034, which of the following is the best conclusion? A) If H 0 is false, the probability of obtaining a test statistic as extreme as or more

extreme than the one actually observed is 0.034. B) The probability that H 0 is false is 0.034. C) The probability that H 0 is true is 0.034. D) If H 0 is true, the probability of obtaining a test statistic as extreme as or more

extreme than the one actually observed is 0.034.

73)

74) A sample of 38 students enroll in a program that claims to improve scores on the

74)

quantitative reasoning portion of the Graduate Record Examination (GRE). The participants take a mock GRE test before the program begins and again at the end to measure their improvement. The mean number of points improved was x = 9. Assume the standard deviation is = 44 and let be the population mean number of points improved. To determine whether the program is effective, a test is made of the hypotheses H 0 : = 0 versus H 1: > 0. Using technology, compute the P-value. A) 0.103671992 B) 1.260902864

C) 0.051835996

D) 0.025917998

75) A new organic pest control formula is being tested on potato plants to see whether it can

75)

reduce the level of potato beetle infestation. The mean number of beetles per untreated plant is 7. It is hoped that the new formula may reduce this infestation rate. State the appropriate null and alternate hypotheses. A) H 0 : < 7, H 1 : = 7 B) H 0 : = 7, H 1 : < 7 C) H 0 :

= 7, H 1:

D) H 0 :

< 7, H 1: > 7

76) A fleet of rental cars - all the same make, model, and year - has a mean fuel efficiency of

23.5 miles per gallon (mpg). A random sample of 51 cars are selected and the air filter of each is replaced with a new one. Let be the population mean fuel efficiency score that would occur if every car's air filter were replaced. The air filter change is deemed effective if > 23.5 mpg. A test is made of H 0 : = 23.5 versus H 1 : > 23.5. Assume that the air filter changes are effective but the conclusion is reached that the changes might not be effective. Which type of error, of any, has occurred? A) No error - correct decision B) Type II C) Mechanical failure D) Type I

76)

77) In a study to determine whether counseling could help people lose weight, a sample of

77)

people experienced a group-based behavioral intervention, which involved weekly meetings with a trained interventionist for a period of six months. The following data are numbers of pounds lost for 14 people. 6.0 22.2

26.4 22.1

4.0 33.1

27.9 12.8

31.4 15.6

26.4 6.9

31.1 27.5

The following is a boxplot for these data. Is it reasonable to assume that the conditions for performing a hypothesis test are satisfied?

A) No

B) Yes

78) In a simple random sample of 27 law students, 11 are women. You wish to determine if

78)

less than half of law students are women. Determine the type of parameter to be tested and compute the test statistic. A) t-test for the mean; test statistic -0.02 B) Test for a standard deviation; test statistic 21.19 C) Test for a proportion; test statistic -0.96 D) z-test for the mean; test statistic -0.02 79) In a simple random sample of 66 families, the mean number of children is 2.3 with a

79)

standard deviation of 0.7. You wish to determine if the population mean differs from 2.1 children per family. Determine the type of parameter to be tested and compute the test statistic. A) t-test for the mean; test statistic 2.3212 B) Test for a standard deviation; test statistic 701.7347 C) Test for a proportion; test statistic 3.5456 D) z-test for the mean; test statistic 2.3212 80) Determine whether the alternative hypothesis is left-tailed, right-tailed, or two-tailed.

H 0: = 77 A) left-tailed

H 1: < 77 B) right-tailed

C) two-tailed

80)

81) The following display from a TI-84 Plus calculator presents the results of a hypothesis

81)

test for a population mean .

< 59 t = -0.570935 p = 0.285088 x = 58.88 Sx = 1.64157 n = 61

Do you reject H 0 at the

= 0.10 level of significance?

A) No

B) Yes

82) A test is made of H 0 :

= 61 versus H 1 : > 61. A sample of size n = 77 is drawn, and

x = 60. The population standard deviation is statistic z. A) -0.05 B) -1.91

= 21. Compute the value of the test C) -0.42

D) 0.34

83) Determine whether the outcome is a Type I error, a Type II error, or a correct decision.

A test is made of H 0: = 53 versus H 1 : is not rejected. A) Type I error

53. The true value of

B) Correct decision

C) Type II error 84)

Test of mu = 43 vs. not = 43 The assumed standard deviation 11.5 Mean 46.53

SE Mean 3.249475

What is the P-value? A) 46.53

95% CI (1.49603395, 14.233977)

B) 3.249475

C) 0.069373

83)

is 52 and H 0

84) The following output from MINITAB presents the results of a hypothesis test.

N 35

82)

Z 1.815979

P 0.069373

D) 1.815979

85) At a water bottling facility, a technician is testing a bottle filling machine that is

85)

supposed to deliver 500 milliliters of water. The technician dispenses 40 samples of water and determines the volume of each sample. The 40 samples have a mean volume of x = 501.6 mL. The machine is out of calibration if the mean volume differs from 500 mL. The technician wants to perform a hypothesis test to determine whether the machine is out of calibration. The standard deviation of the dispensed volume is known to be = 7.1. Compute the value of the test statistic. A) 1.43 B) 0.25 C) 3.80 D) 0.23 86) A test is made of H 0 :

= 49 versus H 1 :

49. A sample of size n = 77 is drawn, and

x = 54. The population standard deviation is statistic z. A) 0.97 B) 1.83

86)

= 24. Compute the value of the test C) 8.96

D) 0.21

87) The following display from a TI-84 Plus calculator presents the results of a hypothesis

87)

test for a population mean .

< 44 t = -1.291799 p = 0.100914 x = 43.83 Sx = 0.98480 n = 56

What is the value of x ? A) 43.83 B) 44

C) -1.291799

D) 0.100914

88) A telecommunications company provided its cable TV subscribers with free access to a

new channel for a month. It then chose a sample of 400 viewers and asked them whether they would be willing to pay an extra $10 per month to continue access to the channel. A total of 25 replied that they would be willing to pay. The marketing director of the company claims that more than 5% of all its subscribers would be willing to pay. Can you conclude that the director's claim is true? Use the = 0.01 level of significance. A) No conclusion is possible. B) No C) Yes

88)

89) The following display from a TI-84 Plus calculator presents the results of a hypothesis

89)

test for a population proportion p.

prop > 0.36 z = -2.76 p = 0.00289 ^

p = 0.205 n = 73

What is the value of the sample proportion p? A) 0.205 B) 73

C) 0.36

D) 0.00289

90) A market research firm reported that the mean annual earnings of all family practitioners

90)

in the United States was $180,439. A random sample of 53 family practitioners in New York that month had mean earnings of x = $192,096 with a standard deviation of $42,108. You wish to test whether family practitioners in New York make more than the national average. State the null and alternate hypotheses. $192,096 A) H 0 : = $192,096, H 1 : C) H 0 :

= $192,096, H 1: > $192,096

B) H 0 :

$180,439, H 1: > $180,439

D) H 0 :

= $180,439, H 1: > $180,439

91) A market research firm reported that the mean annual earnings of all family practitioners

in the United States was $179,055. A random sample of 40 family practitioners in New York that month had mean earnings of x = $197,271 with a standard deviation of $35,551. You wish to test whether family practitioners in New York make more than the national average. State a conclusion regarding H 0 . Use the

= 0.05 level of significance.

A) Do not reject H 0 : there is insufficient evidence to conclude that the mean annual

earnings are greater than the national average. B) Reject H 0 : the mean annual earnings appear to be greater than the national average. C) There is not enough information to draw a conclusion.

91)

92) In an attempt to increase business on Monday nights, a restaurant offers a free dessert

92)

with every dinner order. Before the offer, the mean number of dinner customers on Monday was 150. Following are the numbers of diners on a random sample of Mondays while the offer was in effect. 186 157

178 153

156 168

166 168

167 145

Can you conclude that the mean number of diners increased while the offer was in effect? Use the = 0.05 level of significance and assume the population is normally distributed. A) Reject H 0 . There is sufficient evidence to conclude that the mean number of diners

increased while the offer was in effect. B) Do not reject H 0 . There is insufficient evidence to conclude that the mean number of diners increased while the offer was in effect. C) There is not enough information to draw a conclusion. 93) A tire company claims that the lifetimes of its tires average 50,000 miles. The standard

93)

deviation of tire lifetimes is known to be = 5000 miles. You sample 100 tires and will test the hypothesis H 0 : = 50,000 versus H 1 : < 50,000 at the = 0.01 level of significance. Using technology, find the power of the test against the alternative 1 = 48,000 A) 0.7271 B) 0.9525 C) 2.326 D) 0.7792 94) A garden supplier claims that its new variety of giant tomato produces fruit with a mean

weight of 35 ounces. A test is made of H 0 : = 35 versus H 1 :

35. The null hypothesis

is not rejected. State the appropriate conclusion. A) The mean weight is equal to 35 ounces. B) There is not enough evidence to conclude that the mean weight differs from 35 ounces. C) There is not enough evidence to conclude that the mean weight is 35 ounces. D) The mean weight is not equal to 35 ounces.

94)

95) The following display from a TI-84 Plus calculator presents the results of a hypothesis

95)

test for a population mean .

< 34 t = -3.514974 p = 0.000439 x = 33.68 Sx = 0.68733 n = 57

State the null and alternate hypotheses. 33.68, H 1 : = 33.68 A) H 0 : C) H 0 :

= 34, H 1: = 33.68

B) H 0 :

34, H 1 : = 34

D) H 0 :

= 34, H 1: < 34

96) In a simple random sample of size 70, there were 49 individuals in the category of

96)

interest. It is desired to test H 0: p = 0.81 versus H 1 : p < 0.81. Do you reject H 0 at the 0.01 level? A) Yes 97) A test of H 0 :

B) No

= 45 versus H 1:

45 is performed using a significance level of

97)

= 0.05. The P-value is 0.13. Is H 0 rejected? A) It cannot be determined. B) Yes C) No 98) In a simple random sample of size 80, there were 44 individuals in the category of

98)

interest. It is desired to test H 0: p = 0.45 versus H 1 : p < 0.45. Compute the test statistic z. A) 0.06

B) 5.69

C) 0.55

D) 1.80

99) Determine whether the outcome is a Type I error, a Type II error, or a correct decision.

A test is made of H 0: = 23 versus H 1 : is rejected. A) Type I error

23. The true value of

B) Correct decision

is 22 and H 0

C) Type II error

99)

100) A sample of 95 chewable vitamin tablets have a sample mean of 257 milligrams of

100)

vitamin C. Nutritionists want to perform a hypothesis test to determine how strong the evidence is that the mean mass of vitamin C per tablet exceeds 256 milligrams. State the appropriate null and alternate hypotheses. 256 A) H 0 : = 256, H 1 : B) H 0 : = 256, H 1 : > 256 C) H 0 :

D) H 0 :

> 257, H 1: = 257

< 257, H 1: > 257

101) A machine that fills beverage cans is supposed to put 12 ounces of beverage in each can.

101)

The standard deviation of the amount in each can is 0.10 ounce. The machine is overhauled with new components, and ten cans are filled to determine whether the standard deviation has changed. Assume the fill amounts to be a random sample from a normal population. 11.82 12.11 11.92 12.07 12.12 11.86 12.02 11.85 11.92 11.86 Perform a hypothesis test to determine whether the standard deviation differs from 0.10 ounce. Use the = 0.05 level of significance. A) Do not reject H 0 . B) Reject H 0 . 102) The following display from a TI-84 Plus calculator presents the results of a hypothesis

test.

32 z = -0.612816 p = 0.539998 x = 30.65 n = 37

Do you reject H 0 at the

= 0.05 level?

A) No B) Yes C) There is not enough information to draw a conclusion.

102)

103) The following prices, in dollars, of 7.5-cubic-foot refrigerators were recorded from a

103)

random sample. 282 297

284 384

357 304

304 307

288 297

A consumer organization reports that the mean price of 7.5-cubic-foot refrigerators is greater than $300. Do the data provide convincing evidence of this claim? Use the = 0.01 level of significance and assume the population is normally distributed. A) Reject H 0 .

There is sufficient evidence to conclude that the mean price is greater than $300 B) Do not reject H 0 . There is not sufficient evidence to conclude that the mean price is greater than $300 C) There is not enough information to draw a conclusion. 104) A garden supplier claims that its new variety of giant tomato produces fruit with a mean

weight of 37 ounces. A test is made of H 0 : = 37 versus H 1 :

104)

37. The null hypothesis

is rejected. State the appropriate conclusion. A) There is not enough evidence to conclude that the mean weight differs from 37 ounces. B) The mean weight is not equal to 37 ounces. C) The mean weight is equal to 37 ounces. D) There is not enough evidence to conclude that the mean weight is 37 ounces. 105) Find the P-value for the given test statistic t, sample size n, and alternate hypothesis H 1 .

t = 3.179, n = 11, H 1 :

105)

A) 0.0025 < P < 0.005

B) 0.002 < P < 0.005

C) 0.001 < P < 0.002

D) 0.005 < P < 0.01

106) A simple random sample of the weights of 15 boxes of cookies has mean 16.02 ounces

and standard deviation 0.29 ounces. You wish to determine if the population standard deviation is less than 0.30. Assuming the population is normally distributed, determine the type of parameter to be tested and compute the test statistic. A) z-test for the mean; test statistic -0.0024 B) Test for a standard deviation; test statistic 13.0822 C) t-test for the mean; test statistic -0.0024 D) Test for a proportion; test statistic -0.0845

106)

107) The following display from a TI-84 Plus calculator presents the results of a hypothesis

107)

test.

42 z = 1.415549 p = 0.156908 x = 44.07 n = 44

What is the P-value? A) 0.156908

B) 44.07

C) 42

D) 1.415549

108) Shipments of coffee beans are checked for moisture content. A high moisture content

108)

indicates water contamination and will result in the shipment being rejected. Let represent the mean water content (in percent by weight) in a shipment. Seventy-five moisture measurements will be made on beans chosen at random from the shipment. A test of the hypotheses H 0 : = 11 versus H 1 : > 11 will be made at the = 0.05 level of significance. Assume the standard deviation of moisture content is power of the test against the alternative 1 = 13. A) 0.0455

B) -1.6859

C) 0.9545

= 5.2. Find the D) 0.9770

109) A poll surveyed 711 video gamers, and 142 of them said they prefer playing games on a

console rather than a computer. An executive at a game console company claims that more than 25% of gamers prefer consoles. Does the poll provide convincing evidence that the claim is true? Use the = 0.05 level of significance. A) No conclusion is possible. B) No C) Yes

109)

110) The mean annual tuition and fees for a sample of 13 private colleges was $31,900 with a

110)

standard deviation of $4600 A dotplot shows that it is reasonable to assume that the population is approximately normal. You wish to test whether the mean tuition and fees for private colleges is different from $34,400. State a conclusion regarding H 0 . Use the

= 0.01 level of significance.

A) Reject H 0 . The mean annual tuition and fees appears to be different from $34,400. B) There is not enough information to draw a conclusion. C) Do not reject H 0 .

There is insufficient evidence to conclude that the mean annual tuition and fees is different from $34,400. 111) A test has power 0.80 when 1 = 16. True or false: the probability of making a correct

decision when 1 = 16 is 0.20. A) True

111)

B) False

112) According to a survey, the mean height for men is 69.6 inches. In a sample of 270 men

112)

between the ages of 60 and 69, the mean height was x = 69.2 inches. Public health officials want to determine whether the mean height for older men is less than the mean height of all adult men. Assuming the population standard deviation to be = 2.87 inches, compute the value of the test statistic. A) -2.29 B) 2.29 C) 396.19 D) 0.99 113) A grocery store owner claims that the mean amount spent per checkout is more than $68.

A test is made of H 0: = 68 versus H 1 : > 68. The null hypothesis is not rejected. State the appropriate conclusion. A) There is not enough evidence to conclude that the mean checkout price is less than or equal to $68. B) There is not enough evidence to conclude that the mean checkout price is greater than $68. C) The mean checkout amount is less than or equal to $68. D) The mean checkout amount is greater than $68.

113)

114) A fleet of rental cars - all the same make, model, and year - has a mean fuel efficiency of

114)

27.4 miles per gallon (mpg). A random sample of 40 cars are selected and the air filter of each is replaced with a new one. Let be the population mean fuel efficiency score that would occur if every car's air filter were replaced. The air filter change is deemed effective if > 27.4 mpg. A test is made of H 0 : = 27.4 versus H 1 : > 27.4. Consider these possible conclusions: i). The air filter changes are effective. ii). The air filter changes are not effective. iii). The air filter changes might not be successful. Which of the three conclusions is best if H 0 is rejected? A) iii

B) ii

C) i

115) A fleet of rental cars - all the same make, model, and year - has a mean fuel efficiency of

115)

27.6 miles per gallon (mpg). A random sample of 41 cars are selected and the air filter of each is replaced with a new one. Let be the population mean fuel efficiency score that would occur if every car's air filter were replaced. The air filter change is deemed effective if > 27.6 mpg. A test is made of H 0 : = 27.6 versus H 1 : > 27.6. Assume that the air filter changes are effective. Which type of error is impossible? A) Type II B) Type I 116) Find the P-value for the given test statistic t, sample size n, and alternate hypothesis H 1 .

t = 2.874, n = 9, H 1 : > 0 A) 0.025 < P < 0.05 C) 0.0025 < P < 0.005 117) A test of H 0 :

116)

B) 0.005 < P < 0.01 D) 0.01 < P < 0.025

= 45 versus H 1: < 45 is performed using a significance level of

= 0.05. The value of the test statistic is z = -1.77. Is H 0 rejected? A) It cannot be determined. B) Yes C) No

117)

118) The following output from MINITAB presents the results of a hypothesis test for a

118)

population mean . Test of mu = 39 vs. not = 39 N 55

Mean 36.65

StDev 27.169760

SE Mean 3.66357

95% CI T (29.305028, 43.994972) -0.641451

What are the null and alternate hypotheses? A) H 0 : = 39, H 1 : = 36.65 C) H 0 :

= 36.65, H 1:

B) H 0 : D) H 0 :

36.65

P 0.523943

39, H 1 : = 39 = 39, H 1:

119) The following display from a TI-84 Plus calculator presents the results of a hypothesis

119)

test.

49 z = 1.63 p = 0.050163 x =50.63 n = 61

What are the null and alternate hypotheses? 49 A) H 0 : = 49, H 1 : C) H 0 :

B) H 0 : D) H 0 :

49, H 1 : = 49

50.63 H 1 : = 50.63 = 49, H 1: = 50.63

120) The following output from MINITAB presents the results of a hypothesis test.

120)

Test of mu = 36 vs. not = 36 The assumed standard deviation 14.9 N 54

Mean 32.39

SE Mean 2.23818

95% CI (0.02088867, 8.79455275)

What is the value of the test statistic? A) 0.075010 B) 32.39

C) -1.780401

Z -1.780401

P 0.075010

D) 2.23818

121) A sample of 48 students enroll in a program that claims to improve scores on the

121)

quantitative reasoning portion of the Graduate Record Examination (GRE). The participants take a mock GRE test before the program begins and again at the end to measure their improvement. The mean number of points improved was x = 17. Assume the standard deviation is = 47 and let be the population mean number of points improved. To determine whether the program is effective, a test is made of the hypotheses H 0 : = 0 versus H 1: > 0. Do you reject H 0 at the

= 0.05 level?

A) There is not enough information to draw a conclusion. B) Yes C) No 122) Use technology to find the P-value for the following values of the test statistic t, sample

122)

size n, and alternate hypothesis H 1 . t = 2.357, n = 9, H 1 : A) 0.0231 123) A test of H 0 :

B) 0.0428

= 40 versus H 1:

C) 0.0462

D) 0.0214

40 is performed using a significance level of

123)

= 0.05. The P-value is 0.143. If the true value of is 42, does the conclusion result in a Type I error, a Type II error, or a correct decision? A) Correct decision B) Type II error C) Type I error 124) A test is made of H 0 :

= 47 versus H 1 :

47. A sample of size n = 61 is drawn, and

x = 52. The population standard deviation is = 23. Compute the value of the test statistic z and determine if H 0 is rejected at the = 0.05 level. A) 0.22, H 0 not rejected

B) 0.22, H 0 rejected

C) 1.70, H 0 rejected

D) 1.70, H 0 not rejected

124)

125) According to a survey, the mean height for men is 69.9 inches. In a sample of 280 men

125)

between the ages of 60 and 69, the mean height was x = 69.0 inches. Public health officials want to determine whether the mean height for older men is less than the mean height of all adult men. Assuming the population standard deviation to be = 2.89 inches, do you reject H 0 at the = 0.05 level? A) Yes B) There is not enough information to draw a conclusion. C) No 126) A sample of 48 students enroll in a program that claims to improve scores on the

126)

quantitative reasoning portion of the Graduate Record Examination (GRE). The participants take a mock GRE test before the program begins and again at the end to measure their improvement. The mean number of points improved was x = 22. Assume the standard deviation is = 46 and let be the population mean number of points improved. To determine whether the program is effective, a test is made of the hypotheses H 0 : = 0 versus H 1: > 0. Compute the value of the test statistic. A) 0.0005 B) 22.47

C) 0.48

D) 3.31

127) The Golden Comet is a hybrid chicken that is prized for its high egg production rate and

gentle disposition. According to recent studies, the mean rate of egg production for 1-year-old Golden Comets is 5.2 eggs/week. Sarah has 35 1-year-old hens that are fed exclusively on natural scratch feed: insects, seeds, and plants that the hens obtain as they range freely around the farm. Her hens exhibit a mean egg-laying rate of 5.6 eggs/day. Sarah wants to determine whether the mean laying rate for her hens is higher than the mean rate for all Golden Comets. State the appropriate null and alternate hypotheses. 5.6 A) H 0 : > 5.2, H 1 : = 5.2 B) H 0 : = 5.6, H 1 : C) H 0 :

D) H 0 :

= 5.2, H 1: > 5.2

< 5.6, H 1: = 5.6

127)

128) A fleet of rental cars - all the same make, model, and year - has a mean fuel efficiency of

128)

23.2 miles per gallon (mpg). A random sample of 42 cars are selected and the air filter of each is replaced with a new one. Let be the population mean fuel efficiency score that would occur if every car's air filter were replaced. The air filter change is deemed effective if > 23.2 mpg. A test is made of H 0 : = 23.2 versus H 1 : > 23.2. Assume that the air filter changes are not effective. Which type of error is impossible? A) Type I B) Type II 129) A test of H 0 :

= 61 versus H 1: < 61 is performed using a significance level of

129)

= 0.01. The P-value is 0.012. Is H 0 rejected? A) No B) It cannot be determined. C) Yes 130) The following display from a TI-84 Plus calculator presents the results of a hypothesis

130)

test for a population mean .

< 33 t = -1.505947 p = 0.069186 x = 32.60 Sx = 1.89686 n = 51

How many degrees of freedom are there? A) 33 B) 50

C) 51

D) 52

131) Find the critical values for the following values of the significance level , sample size n,

131)

and alternate hypothesis H 1 . = 0.05, n = 13, H 1 : A) -2.179, 2.179

B) -1.645, 1.645

C) -2.160, 2.160

D) -1.782, 1.782

132) In a simple random sample of size 70, there were 24 individuals in the category of ^

interest. Compute the sample proportion p. A) 94 B) 0.522

C) 0.657

D) 0.343

132)

133) According to a survey, the mean height for men is 69.3 inches. In a sample of 320 men

133)

between the ages of 60 and 69, the mean height was x = 69.2 inches. Public health officials want to determine whether the mean height for older men is less than the mean height of all adult men. Assuming the population standard deviation to be = 2.88 inches, compute the P-value. A) 0.7324 B) 0.5352 C) -0.6211 D) 0.2676 134) A machine that fills beverage cans is supposed to put 12 ounces of beverage in each can.

134)

The amounts measured in a simple random sample of eight cans are: 11.95 12.11 12.06 12.12 11.96 12.07 11.93 12.05 The following is a dotplot for these data. Is it reasonable to assume the conditions for performing a hypothesis test are satisfied?

A) Yes

B) No

135) The following display from a TI-84 Plus calculator presents the results of a hypothesis

135)

test for a population proportion p.

prop > 0.31 z = -2.54 p = 0.005543 ^

p = 0.187 n = 91

State the null and alternate hypotheses. A) H 0 : p = 0.005543, H 1 : p > 0.005543

B) H 0 : p = 0.31, H 1: p > 0.31

C) H 0 : p = 0.187, H 1 : p > 0.187

D) H 0 : p = 0.187, H 1 : p = 0.31

136) A test has power 0.75 when 1 = 15. True or false: the probability of making a correct

decision when 1 = 15 is 0.75. A) True

B) False

136)

137) A test is made of H 0 :

= 42 versus H 1 : > 42. A sample of size n = 61 is drawn, and

137)

x = 47. The population standard deviation is = 29. Compute the value of the test statistic z and determine if H 0 is rejected at the = 0.05 level. A) 0.17, H 0 not rejected

B) 1.35, H 0 rejected

C) 1.35, H 0 not rejected

D) 0.17, H 0 rejected

138) The following output from MINITAB presents the results of a hypothesis test for a

138)

population mean . Test of mu = 43 vs. not = 43 N 41

Mean 39.75

StDev 5.309995

What is the value of x? A) 11.6

SE Mean 0.829282

95% CI T (38.073952, 41.426048) -3.919053

B) 43

C) 39.75

P 0.000339

D) 0.000339

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 139) When presenting the results of a hypothesis test, one should report the P-value or the

139)

value of the test statistic. 140) The probability of a Type II error is

, the significance level.

140)

Answer Key Testname: C9

1) B 2) B 3) B 4) B 5) C 6) B 7) B 8) B 9) B 10) C 11) B 12) C 13) B 14) A 15) B 16) C 17) C 18) B 19) C 20) B 21) A 22) A 23) B 24) D 25) B 26) A 27) i). 0.600

ii). -1.95 iii). Yes 28) i). z = 3.1818 ii). P = 0.0007 iii). Yes 29) i). H 0 : p = 0.24, H 1 : p

0.24

ii). -1.89 iii). Yes 30) i). H 0 : = 500, H 1 :

500

ii). -3.20 iii). Reject H 0. The machine appears to be out of calibration. 31) i). z = 2.1469 ii). P = 0.0159 iii). Yes

Answer Key Testname: C9

32) i). H 0 :

= 31,400, H 1 :

31,400

ii). 3.184; 13 degrees of freedom iii). Reject H 0. The mean annual tuition and fees appears to be different from $31,400. 33) i. H 0 :

= 4.7, H 1: > 4.7

ii. z = 4.06 iii. Reject H 0 . We conclude that the mean rate of egg production for Sarah's hens is greater than the mean rate for the population of all hens. 34) i) H 0 : = $177,156, H 1 : > $177,156 ii) 6.650; 35 degrees of freedom iii) Reject H 0: there is sufficient evidence to conclude that the mean annual earnings are greater than the national average. 35) B 36) D 37) B 38) B 39) D 40) A 41) B 42) C 43) B 44) B 45) C 46) D 47) D 48) C 49) B 50) B 51) A 52) A 53) B 54) D 55) B 56) A 57) A 58) B 59) B 60) C 61) A 62) B 63) B 64) D 65) C 66) C 67) A 39

Answer Key Testname: C9

68) C 69) C 70) D 71) A 72) A 73) D 74) A 75) B 76) B 77) B 78) C 79) A 80) A 81) A 82) C 83) C 84) C 85) A 86) B 87) A 88) B 89) A 90) D 91) B 92) A 93) B 94) B 95) D 96) A 97) C 98) D 99) B 100) B 101) A 102) A 103) B 104) B 105) D 106) B 107) A 108) C 109) B 110) C 111) B 112) A 113) B 114) C 115) B 116) D 117) B 40

Answer Key Testname: C9

118) D 119) A 120) C 121) B 122) C 123) B 124) D 125) A 126) D 127) C 128) B 129) A 130) B 131) A 132) D 133) D 134) A 135) B 136) A 137) C 138) C 139) TRUE 140) FALSE

Exam Name___________________________________

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) A sample of students is enrolled in an online statistics class, and another sample is

enrolled in a traditional statistics class. At the end of the semester, the students are given a test. The scores from each sample are compared to determine which class was more effective. Are these samples independent or paired? A) Paired B) Independent 2) A sample of students is enrolled in a speed-reading class. Each takes a reading test

before and again after the class. The two samples of scores are compared to determine how large an improvement in reading speed occurred. Are these samples independent or paired? A) Independent B) Paired 3) Traffic engineers compared rates of traffic collisions at intersections with raised medians

and rates at intersections with two-way left-turn lanes. They found that out of 4606 collisions at intersections with raised medians, 2275 were rear-end collisions, and out of 4559 collisions at two-way left-turn lanes, 2029 were rear-end collisions. Assuming these to be random samples of collisions from the two types of intersections, construct a 90% confidence interval for the difference between the proportions of collisions that are of the rear-end type at the two types of intersection. A) (0.041, 0.057) B) (0.032, 0.066) C) (0.494, 0.445) D) (0.477, 0.511) 4) The following output from MINITAB presents a confidence interval for the mean

difference between matched pairs. N Mean Difference 14 3.2680

StDev 7.2315

SEMean 1.9327

95% CI for mean difference: (-0.907337, 7.443337) How many degrees of freedom are there? A) 7.2315 B) 13

C) 14

D) 1.9327

5) A group of six individuals with high blood pressure volunteered to test whether petting

cats for 10 minutes can alter systolic blood pressure levels. Systolic blood pressures (in millimeters of mercury, or mmHg) were measured for each subject before and after petting cats for 10 minutes, with the following results: Individual

Before

After

1 2 3 4 5 6

168 160 146 160 167 158

144 133 133 137 130 141

A researcher claims that the mean reduction in systolic blood pressure is 19 mmHg. Does the 95% confidence interval contradict this claim? (Hint: you need to find the 95% confidence interval for the mean reduction in systolic blood pressure.) A) No B) Yes 6) An amateur golfer wishes to determine if there is a difference between the drive

distances of her two favorite drivers. (A driver is a specialized club for driving the golf ball down range.) She hits fourteen balls with driver A and 10 balls with driver B. The drive distances (in yards) for the trials are show below. Driver A 283 296 258 268 250 224 232 265 274 275 268 245 242 273 Driver B 256 292 296 220 215 218 280 206 227 199 Assume that the populations are approximately normal. Construct a 98% confidence interval for the difference between the mean drive distances for the two drivers. Based on your results, is it reasonable to conclude that the mean drive distances may be the same for drivers A and B? A) No B) Yes

7) A group of six individuals with high blood pressure volunteered to test whether petting

Before

After

1 2 3 4 5 6

162 190 177 137 182 183

150 166 126 144 136 124

Find the 99% confidence interval for the mean reduction in systolic blood pressure. A) (-19.63, 81.29) B) (-11.22, 72.88) (-15.84, -19.63) C) D) (-12.06, 77.51) 8) A sample of students is enrolled in an online statistics class, and another sample is

enrolled in a traditional statistics class. At the end of the semester, the students are given a test. The scores from each sample are compared to determine which class was more effective. Are these samples independent or paired? A) Independent B) Paired 9) Using technology, solve the following problem: A survey of college students reported

that in a sample of 378 male students, the average number of energy drinks consumed per month was 2.68 with a standard deviation of 4.58, and in a sample of 272 female students, the average was 1.30 with a standard deviation of 3.14. Construct a 98% confidence interval for the difference between men and women in the mean number of energy drinks consumed. A) (0.5909, 2.1691) B) (0.6755, 2.0845) C) (-5.0523, 7.8123) D) (0.6050, 2.1550)

10) The following display from a TI-84 Plus calculator presents a 95% confidence interval

10)

for the difference between two means. The sample sizes are n1 = 8 and n2 = 13.

(21.600, 62.464) df = 15.759542 x1 = 123.288 x2 = 81.256 Sx1 = 22.593 Sx2 = 24.150

Compute the point estimate of 1 - 2 . A) 42.032 B) 123.288

C) 40.864

D) -1.557

11) A survey of college students reported that in a sample of 362 male students, the average

11)

number of energy drinks consumed per month was 2.30 with a standard deviation of 4.71, and in a sample of 308 female students, the average was 1.50 with a standard deviation of 3.08. Construct a 90% confidence interval for the difference between men and women in the mean number of energy drinks consumed. Based on your results, is it reasonable to believe that the mean number of energy drinks consumed may be the same for both male and female students? A) Yes B) No 12) In an agricultural experiment, the effects of two fertilizers on the production of oranges

were measured. Fourteen randomly selected plots of land were treated with fertilizer A, and 10 randomly selected plots were treated with fertilizer B. The number of pounds of harvested fruit was measured from each plot. Following are the results. Fertilizer A 530 535 485 509 436 545 588 568 510 499 504 528 525 509 Fertilizer B 494 402 468 491 496 469 504 424 479 473 Assume that the populations are approximately normal. Construct a 95% confidence interval for the difference between the mean yields for the two types of fertilizer. Based on your results, is it reasonable to conclude that the mean yields may be the same for fertilizers A and B? A) No B) Yes 4

12)

13) The following MINITAB output display presents a 95% confidence interval for the

13)

difference between two proportions. Sample X 1 69 2 118

N 977 928

Sample P 0.070624 0.127155

Difference = p(1) - p(2) Estimate for difference: -0.056531 95% CI for difference: (-0.079, -0.034) Fill in the blanks: We are 95% confident that the difference between the proportions is between ______ and ______. A) -0.079, -0.034 B) 0.070624, 0.127155 C) 928, 977 D) -0.056531, 0 14) The following MINITAB output display presents a 95% confidence interval for the

difference between two means. N Mean StDev A 15 144.384 25.413 B 9 168.966 22.669 Difference = mu (A) - mu (B) Estimate for difference: -24.582 95% CI for difference: (-44.197, -4.967)

14)

SE Mean 6.562 7.556

DF = 19

Fill in the blanks: We are 95% confident that the difference in the means is between ______ and ______. A) 9, 15 B) 0, 19 C) -44.197, -4.967 D) 144.384, 168.966 15) The concentration of hexane (a common solvent) was measured in units of micrograms

per liter for a simple random sample of thirteen specimens of untreated ground water taken near a municipal landfill. The sample mean was 424.2 with a sample standard deviation of 6.5. Fourteen specimens of treated ground water had an average hexane concentration of 246.0 with a standard deviation of 5.9. It is reasonable to assume that both samples come from populations that are approximately normal. Construct a 99% confidence interval for the reduction of hexane concentration after treatment. A) (175.6, 180.8) B) (175.1, 181.3) C) (170.9, 185.5) D) (176.7, 179.7)

15)

16) Using technology, solve the following problem: In an agricultural experiment, the effects

16)

of two fertilizers on the production of oranges were measured. Fourteen randomly selected plots of land were treated with fertilizer A, and 10 randomly selected plots were treated with fertilizer B. The number of pounds of harvested fruit was measured from each plot. Following are the results. Fertilizer A 537 480 424 511 439 470 421 420 489 512 494 448 468 526 Fertilizer B 429 429 383 427 426 460 407 437 394 494 Assume that the populations are approximately normal. Construct a 98% confidence interval for the difference between the mean yields for the two types of fertilizer. A) (4.443, 86.786) B) (8.987, 82.241) C) (19.740, 7531.810) D) (80.766, 6763.582) 17) The following display from a TI-84 Plus calculator presents a 95% confidence interval

17)

for the difference between two proportions.

(-0.015, 0.057) ^

p1 = 0.085315 ^

p2 = 0.064140 n1 = 715 n2 = 686

Compute the point estimate of p1 - p2 . A) 0.021175

B) 1401

C) 29

D) 0.072

18) Construct the confidence interval for the difference 1 - 2 for the given level and values

18)

of x1, x2 , s1 , s2, n1 , and n2 . Level 90%, x1 = 91.6, x2 = 79.2, s1 = 7.1, s2 = 7.3, n1 =15, and n2 = 11 A) (10.8, 14.0)

B) (7.2, 17.6)

C) (9.0, 15.8)

D) (10.3, 14.5)

19) A sample of students is enrolled in a speed-reading class. Each takes a reading test

before and after the class. The two samples of scores are compared to determine how large an improvement in reading speed occurred. Are these samples independent or paired? A) Independent B) Paired 6

19)

20) The following MINITAB output display presents a 95% confidence interval for the

difference between two means. N Mean StDev A 13 111.071 22.131 B 15 97.224 26.446 Difference = mu (A) - mu (B) Estimate for difference: 13.847 95% CI for difference: (-4.149, 31.843)

20)

SE Mean 6.138 6.828

DF = 26

How many degrees of freedom did MINITAB use? A) 28 B) 35.992 C) 26

D) 13.847

21) The following MINITAB output display presents a 95% confidence interval for the

21)

difference between two proportions. Sample X 1 100 2 78

N 708 898

Sample P 0.141243 0.086860

Difference = p(1) - p(2) Estimate for difference: 0.054383 95% CI for difference: (0.028, 0.081) What is the point estimate of p1 – p2 ? A) 0.053 B) 0.054383

C) 0.228103

D) 0.111

22) Traffic engineers compared rates of traffic collisions at intersections with raised medians

22)

and rates at intersections with two-way left-turn lanes. They found that out of 4465 collisions at intersections with raised medians, 2210 were rear-end collisions, and out of 4606 collisions at two-way left-turn lanes, 2004 were rear-end collisions. Assuming these to be random samples of collisions from the two types of intersections, construct a 99% confidence interval for the difference between the proportions of collisions that are of the rear-end type at the two types of intersection. Does the confidence interval contradict the claim that the proportion of rear-end collisions is the same at both types of intersection? A) Yes B) No 23) Construct the confidence interval for the difference p1 – p2 for the given level and values

of x1, n1 , x2 , and n2 . Level 95%: x1 = 38, n1 = 50, x2 = 26, n2 = 58 A) (0.157, 0.467)

B) (0.143, 0.481)

C) (0.148, 0.476)

D) (0.137, 0.486)

23)

24) Using technology, solve the following problem: An amateur golfer wishes to determine

24)

if there is a difference between the drive distances of her two favorite drivers. (A driver is a specialized club for driving the golf ball down range.) She hits fourteen balls with driver A and 10 balls with driver B. The drive distances (in yards) for the trials are show below. Driver A 259 198 218 229 227 233 224 266 261 207 236 193 260 217 Driver B 174 257 221 272 273 201 216 299 210 256 Assume that the populations are approximately normal. Construct a 95% confidence interval for the difference between the mean drive distances for the two drivers. A) (1386.82, 509.86) B) (1016.33, 296.53) C) (-31.88, 17.22) D) (-37.24, 22.58) 25) The following MINITAB output display presents a 95% confidence interval for the

difference between two means. N Mean StDev A 9 55.539 23.660 B 7 89.948 25.488 Difference = mu (A) - mu (B) Estimate for difference: -34.409 95% CI for difference: (-58.811, -10.007) What is the point estimate of 1 - 2? A) -48.804 B) 13

SE Mean 7.887 9.634

DF = 13

C) 89.948

D) -34.409

25)

26) A group of six individuals with high cholesterol levels were given a new diet designed to

26)

lower cholesterol levels. Cholesterol levels, in milligrams per deciliter, were measured before and after the implementation of the diet for each individual, with the following results: Individual

Before

After

1 2 3 4 5 6

247 262 264 249 265 272

229 216 236 237 224 223

Find the 95% confidence interval for the mean reduction in cholesterol level. A) (15.91, 50.37) B) (13.33, 51.34) C) (14.29, 13.33) D) (16.23, 48.44) 27) The following output from MINITAB presents a confidence interval for the mean

difference between matched pairs. N Mean Difference 19 7.4321

StDev 2.8390

27)

SEMean 0.651311

95% CI for mean difference: (6.06375, 8.80045) What is the point estimate of d? A) 18 B) 0.651311

C) 7.4321

D) 2.8390

28) The following display from a TI-84 Plus calculator presents a 95% confidence interval

for the difference between two proportions.

(-0.018, 0.029) ^

p1 = 0.082071 ^

p2 = 0.076324 n1 = 792 n2 = 642

Fill in the blanks: We are 95% confident that the difference between two proportions is between _______ and _______. A) 0, 1434 B) -0.018, 0.029 C) 642, 792 D) 0.076324, 0.082071

28)

29) A computer software magazine compares the rates of malware infection for computers

29)

protected by security software A with the rates of infection for computers protected by security software B. They found that out of 827 computers with security software A, 72 became infected with some type of malware after 1000 hours of internet interaction. For security software B, 30 out of 546 computers became infected after 1000 hours of internet interaction. Assuming these to be random samples of infection rates for the two security software packages, construct a 98% confidence interval for the difference between the proportions of infection for the two types of security software packages. A) (0.006, 0.058) B) (0.002, 0.062) C) (0.001, 0.063) D) (0.003, 0.061) 30) The following display from a TI-84 Plus calculator presents a 95% confidence interval

30)

for the mean difference between matched pairs.

(6.714808, 13.817792) x = 10.2663 Sx = 7.5884 n = 20

Fill in the blanks: We are 95% confident that the mean difference is between ______ and ______. A) 2.6779, 17.8547 B) 0, 10.2663 6.714808, 13.817792 C) D) 0, 20 31) The following output from MINITAB presents a confidence interval for the mean

difference between matched pairs. N Mean Difference 16 4.9474

StDev 6.3070

SEMean 1.57675

95% CI for mean difference: (1.586646, 8.308154) Fill in the blanks: We are 95% confident that the mean difference is between ______ and ______. A) 0, 4.9474 B) -1.3596, 11.2544 C) 1.586646, 8.308154 D) 1.57675, 6.3070

31)

32) A computer software magazine compares the rates of malware infection for computers

32)

protected by security software A with the rates of infection for computers protected by security software B. They found that out of 911 computers with security software A, 47 became infected with some type of malware after 1000 hours of internet interaction. For security software B, 23 out of 603 computers became infected after 1000 hours of internet interaction. Assuming these to be random samples of infection rates for the two security software packages, construct a 98% confidence interval for the difference between the proportions of infection for the two types of security software packages. Does the confidence interval contradict the claim that the proportion of infections is the same for the two types of security software? A) Yes B) No 33) A group of six individuals with high cholesterol levels were given a new diet designed to

33)

lower cholesterol levels. Cholesterol levels, in milligrams per deciliter, were measured before and after the implementation of the diet for each individual, with the following results: Individual

Before

After

1 2 3 4 5 6

285 247 264 268 254 262

226 222 218 223 232 227

A dietician claims that the mean reduction in cholesterol level is 27 milligrams per deciliter. Does the 95% confidence interval contradict this claim? (Hint: you need to find the 95% confidence interval for the mean reduction in cholesterol level.) A) Yes B) No 34) In a random sample of 60 patients undergoing a standard surgical procedure, 13 required

medication for postoperative pain. In a random sample of 85 patients undergoing a new procedure, only 13 required medication. Construct a 99% confidence interval for the difference in the proportions of patients needing pain medication between the old and new procedures. A) (0.047, 0.387) B) (-0.106, 0.234) C) (0.025, 0.103) D) (0.217, 0.153)

34)

35) The following display from a TI-84 Plus calculator presents a 95% confidence interval

35)

for the difference between two means. The sample sizes are n1 = 13 and n2 = 8.

(-71.757, -27.649) df = 13.038055 x1 = 110.794 x2 = 160.497 Sx1 = 22.420 Sx2 = 26.525

Fill in the blanks: We are 95% confident that the difference between the means is between _________ and _________. A) 0, 13.038055 B) 110.794, 160.497 C) -71.757, -27.649 D) 22.420, 26.525 36) In an agricultural experiment, the effects of two fertilizers on the production of oranges

36)

were measured. Fourteen randomly selected plots of land were treated with fertilizer A, and 10 randomly selected plots were treated with fertilizer B. The number of pounds of harvested fruit was measured from each plot. Following are the results. Fertilizer A 473 507 526 479 477 468 516 467 519 523 483 540 518 488 Fertilizer B 455 501 470 420 483 419 468 476 459 413 Assume that the populations are approximately normal. Construct a 95% confidence interval for the difference between the mean yields for the two types of fertilizer. A) (14.0, 70.9) B) (16.4, 68.6) C) (20.3, 64.6) D) (19.0, 65.9) 37) Two microprocessors are compared on a sample of 6 benchmark codes to determine

whether there is a difference in speed. The times (in seconds) used by each processor on each code are given below: Code Processor A Processor B

26.5 26.6

10.9 15.4

26.9 28.8

21.6 28.8

17.2 16.7

18.1 11.3

Find the 90% confidence interval for the difference between the mean speeds. A) (-5.45, 3.32) B) (-5.69, 3.56) C) (-5.02, 2.88) D) (-5.22, 3.08) 12

37)

38) Using technology, solve the following problem: The concentration of hexane (a common

38)

solvent) was measured in units of micrograms per liter for a simple random sample of fourteen specimens of untreated ground water taken near a municipal landfill. The sample mean was 241.8 with a sample standard deviation of 8.8. Ten specimens of treated ground water had an average hexane concentration of 149.5 with a standard deviation of 7.4. It is reasonable to assume that both samples come from populations that are approximately normal. Construct a 95% confidence interval for the reduction of hexane concentration after treatment. A) (9.306, 9.900) B) (9.242, 9.960) C) (85.407, 99.193) D) (86.595, 98.005) 39) The following display from a TI-84 Plus calculator presents a 95% confidence interval

39)

for the difference between two means. The sample sizes are n1 = 10 and n2 = 15.

(-62.526, -21.222) df = 19.678187 x1 = 80.827 x2 = 122.701 Sx1 = 25.633 Sx2 = 26.072

How many degrees of freedom did the calculator use? A) 19.678187 B) -0.439 C) 80.827

D) -41.874

40) Using technology, construct the confidence interval for the difference 1 - 2 for the

given level and values of x1 , x2 , s1 , s2 , n1 , and n2. Level 98%, x1 = 26.4, x2 = 22.9, s1 = 7.0, s2 = 5.4, n1 =20, and n2 = 21 A) (-1.271, 8.271)

B) (2.869, 0.666)

C) (-1.232, 8.231)

D) (-0.444, 7.444)

40)

41) The following display from a TI-84 Plus calculator presents a 95% confidence interval

41)

for the mean difference between matched pairs.

(0.003473, 7.144727) x = 3.5741 Sx = 7.4082 n = 19

What is the point estimate of d? A) 3.5741 B) 19

C) 7.141254

D) 7.4082

42) The following display from a TI-84 Plus calculator presents a 95% confidence interval

42)

for the mean difference between matched pairs.

(0.434439, 6.192961) x = 3.3137 Sx = 5.4034 n = 16

How many degrees of freedom are there? A) 3.3137 B) 5.4034

C) 16

D) 15

43) A survey of college students reported that in a sample of 388 male students, the average

number of energy drinks consumed per month was 2.61 with a standard deviation of 4.73, and in a sample of 69 female students, the average was 1.29 with a standard deviation of 3.21. Construct a 99% confidence interval for the difference between men and women in the mean number of energy drinks consumed. A) (-0.03, 2.67) B) (0.05, 2.59) C) (0.15, 2.49) D) (-9.27, 11.91)

43)

44) Two microprocessors are compared on a sample of 6 benchmark codes to determine

44)

whether there is a difference in speed. The times (in seconds) used by each processor on each code are given below: Code Processor A Processor B

21.5 26.9

10.8 11.8

21.6 21.2

24.0 22.9

12.5 11.8

14.9 15.4

An electronics engineer claims that the mean speed is the same for both processors. Does the 95% confidence interval contradict this claim? (Hint: First find the 95% confidence interval for the difference between the mean speeds.) A) Yes B) No 45) In a random sample of 65 patients undergoing a standard surgical procedure, 16 required

45)

medication for postoperative pain. In a random sample of 85 patients undergoing a new procedure, only 16 required medication. Construct a 95% confidence interval for the difference in the proportions of patients needing pain medication between the old and new procedures. A physician claims that the proportion of patients who need pain medication is the same for both procedures. Does the confidence interval contradict the claim? A) No B) Yes 46) An amateur golfer wishes to determine if there is a difference between the drive

distances of her two favorite drivers. (A driver is a specialized club for driving the golf ball down range.) She hits fourteen balls with driver A and 10 balls with driver B. The drive distances (in yards) for the trials are show below. Driver A 279 295 273 266 262 269 273 305 268 248 241 244 248 308 Driver B 271 238 276 258 272 289 228 295 230 289 Assume that the populations are approximately normal. Construct a 90% confidence interval for the difference between the mean drive distances for the two drivers. A) (-12.6, 23.2) B) (-11.0, 21.6) C) (-13.5, 24.1) D) (-9.9, 20.5)

46)

Answer Key Testname: C10

1) B 2) B 3) B 4) B 5) A 6) B 7) B 8) A 9) B 10) A 11) B 12) A 13) A 14) C 15) C 16) A 17) A 18) B 19) B 20) C 21) B 22) A 23) D 24) C 25) D 26) D 27) C 28) B 29) C 30) C 31) C 32) B 33) B 34) B 35) C 36) B 37) C 38) C 39) A 40) A 41) A 42) D 43) C 44) B 45) A 46) A

Exam Name___________________________________

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) The compressive strength, in kilopascals,was measured for concrete blocks from five

different batches of concrete, both three and six days after pouring. The data are as follows:

After 3 days After 6 days

Block 1 1338 1376

Block 2 1318 1375

Block 3 1353 1369

Block 4 1352 1385

Block 5 1329 1361

Can you conclude that the mean strength after three days differs from the mean strength after six days? Use H 0 : d = 0, H 1: d 0 to state a conclusion. Use the = 0.05 level of significance and the critical value method. A) Reject H 0 .

B) Do not reject H 0 .

2) In a study of birth order and intelligence, IQ tests were given to 18- and 19-year-old men

to estimate the size of the difference, if any, between the mean IQs of firstborn sons and secondborn sons. The following data for 10 firstborn sons and 10 secondborn sons are consistent with the means and standard deviations reported in the article. Assume that the samples come from normal populations.

104 89

Firstborn 82 102 96 114 107 89

129 103

103 103

Secondborn 103 91 113 92 90 114

102 113

Can you conclude that the standard deviation of IQ differs between firstborn and secondborn sons? Use the = 0.05 level. A) No B) Yes

3) Following are weights in pounds for random samples of 25 newborn baby boys and baby

girls born in Denver. Boxplots indicate that the samples come from populations that are approximately normal.

6.6 6.4 7.8

7.7 6.6 6.3

5.9 8.4 8.6

7.0 6.4 5.9

6.4 8.5 7.7

Boys 7.6 6.4 6.9 6.3 7.4 7.7

8.1 7.4 8.1

7.9 7.8 6.4

8.3 7.5

7.3 6.9

8.2 8.5 8.1

Girls 7.4 6.0 7.2 6.9 8.2 6.7

6.7 8.2 6.2

8.2 6.5 7.7

7.5 6.7

5.7 7.2

Can you conclude that the mean weights differ between boys and girls? Use the level of significance and the critical value method. A) Reject H 0 . B) Do not reject H 0 .

= 0.01

4) The multiple testing problem states that as more hypothesis tests are performed, small

P-values become

meaningful.

A) more 5) Find f

0.01

A) 4.10

B) less 5)

for F 12,8 . B) 11.19

C) 2.50

D) 5.67

6) In August and September 2005, Hurricanes Katrina and Rita caused extraordinary

flooding in New Orleans, Louisiana. Many homes were severely damaged or destroyed, and of those that survived, many required extensive cleaning. It was thought that cleaning flood-damaged homes might present a health hazard due to the large amounts of mold present in many of the homes. In a sample of 371 residents of Orleans Parish who had participated in the cleaning of one or more homes, 71 had experienced symptoms of wheezing, and in a sample of 181 residents who had not participated in cleaning, 20 reported wheezing symptoms (numbers read from a graph). Can you conclude that the proportion of residents with wheezing symptoms is greater among those who participated in the cleaning of flood-damaged homes? Use the = 0.05 level of significance and the critical value method. A) Reject H 0 . B) Do not reject H 0 .

7) A study was done of a generic and a brand name antifungal ointment to determine

whether there was a difference in the amounts of active ingredient absorbed into the skin. Both the brand name and generic products were applied to the arms of 14 subjects, and the amounts absorbed, in g/cm2, were measured. The results are presented in the following table. Subject Brand Name 2.22 1 1.71 2 1.96 3 2.81 4 1.11 5 3.19 6 2.30 7 4.06 8 2.92 9 2.94 10 2.80 11 3.42 12 2.70 13 3.75 14

Generic 1.44 1.93 2.57 2.26 1.18 3.00 2.76 3.68 2.86 2.86 2.42 3.14 2.61 2.82

Can you conclude that the mean amount absorbed differs between the brand name and the generic drug? Use H 0: d = 0, H 1 : d 0 to state a conclusion. Use the = 0.01 level of significance and the critical value method. A) Do not reject H 0 .

B) Reject H 0 .

8) Medical researchers conducted a study to determine whether treadmill exercise could

improve the walking ability of patients suffering from claudication, which is pain caused by insufficient blood flow to the muscles of the legs. A sample of 48 patients walked on a treadmill for six minutes every day. After six months, the mean distance walked in six minutes was 342 meters, with a standard deviation of 80 meters. For a control group of 46 patients who did not walk on a treadmill, the mean distance was 315 meters with a standard deviation of 88 meters. Can you conclude that the mean distance walked for patients using a treadmill is greater than the mean for the controls? Use the = 0.05 level of significance and the the critical value method. A) Do not reject H 0 . B) Reject H 0 .

9) Angioplasty is a medical procedure in which an obstructed blood vessel is widened. In

some cases, a wire mesh tube, called a stent, is placed in the vessel to help it remain open. A study was conducted to compare the effectiveness of a bare metal stent with one that has been coated with a drug designed to prevent reblocking of the vessel. A total of 5313 patients received bare metal stents, and of these, 828 needed treatment for reblocking within a year. A total of 1134 received drug-coated stents, and 115 of them required treatment within a year. Can you conclude that the proportion of patients who needed retreatment is less for those who received drug-coated stents? Use the = 0.05 level of significance and the critical value method. A) Reject H 0 . B) Do not reject H 0 . 10) In a study of birth order and intelligence, IQ tests were given to 18- and 19-year-old men

to estimate the size of the difference, if any, between the mean IQs of firstborn sons and secondborn sons. The following data for 10 firstborn sons and 10 secondborn sons are consistent with the means and standard deviations reported in the article. It is reasonable to assume that the samples come from populations that are approximately normal.

103 89

Firstborn 81 101 96 114 108 88

121 103

103 104

Secondborn 102 91 112 93 89 114

103 112

Can you conclude that there is a difference in mean IQ between firstborn and secondborn sons? Use the = 0.01 level of signigficance and the critical value method. A) Reject H 0 . B) Do not reject H 0 .

10)

11) Six bean plants had their carbohydrate concentrations (in percent by weight) measured

11)

both in the shoot and in the root. The following results were obtained: Plant 1 2 3 4 5 6

Shoot 4.43 5.81 4.68 4.77 5.24 4.74

Root 3.64 5.52 3.94 4.47 4.69 3.91

Can you conclude that there is a difference in mean concentration between the shoot and the root? Use H 0 : d = 0, H 1: d 0 to state a conclusion. Use the = 0.05 level of significance and the critical value method. A) Do not reject H 0 .

B) Reject H 0 .

12) The concentration of benzene was measured in units of milligrams per liter for a simple

12)

random sample of five specimens of untreated wastewater produced at a gas field. The sample mean was 7.6 with a sample standard deviation of 1.5. Seven specimens of treated wastewater had an average benzene concentration of 3.3 with a standard deviation of 1.6. It is reasonable to assume that both samples come from populations that are approximately normal. Can you conclude that the mean benzene concentration is less in treated water than in untreated water? Use the = 0.05 level of significance and the critical value method. A) Do not reject H 0 . B) Reject H 0 . 13) A new postsurgical treatment was compared with a standard treatment. Seven subjects

13)

received the new treatment, while seven others (the controls) received the standard treatment. The recovery times, in days, are given below. Treatment: Control:

13 17

14 22

16 25

20 29

20 31

21 34

23 38

Can you conclude that the mean recovery time for those receiving the new treatment is less than the mean for those receiving the standard treatment? Use the = 0.05 level of signigficance and the critical value method. A) Reject H 0 . B) Do not reject H 0 . 14) Find the critical value f A) 2.58

0.05

14)

for F 7,20.

B) 3.01

C) 2.51

D) 2.04

15) Find the critical value f A) 2.56

0.01

15)

for F 8,9 .

B) 10.37

C) 5.91

D) 5.47

16) Measurements of the sodium content in samples of two brands of chocolate yielded the

16)

following results (in grams). Brand A: 34 31 37 28 33 32 34 34 30 Brand B: 46 40 42 40 36 38 34 42 32 32 34 22 44 Can you conclude that the sodium content is more variable in Brand B? Use the level of significance. A) No B) Yes

= 0.01

17) A group of eight individuals with high cholesterol levels were given a new drug that was

designed to lower cholesterol levels. Total cholesterol levels, in mg/dL, were measured before and after treatment, with the following results. Subject 1 2 3 4 5 6 7 8

Before 284 300 275 282 250 277 291 277

After 217 204 186 213 177 215 195 197

Can you conclude that the mean cholesterol level is reduced by more than 65 mg/dL after treatment? Use H 0: d = 65, H 1 : d > 65 to state a conclusion. Use the = 0.05 level of significance and the critical value method. A) Reject H 0 .

B) Do not reject H 0 .

17)

18) An automobile manufacturer wants to compare the life times of two brands of tire. She

18)

obtains samples of seven tires of each brand. On each of seven cars, she mounts one tire of each brand on each front wheel. The cars are driven until only 20% of the original tread remains. The distances, in thousands of miles, for each tire are presented in the following table. Car 1 2 3 4 5 6 7

Brand A Brand B 36.9 34.3 45.3 42.2 36.2 35.5 32.1 31.9 37.2 38.1 48.3 47.8 38.2 33.2

Brand A is more expensive than Brand B. State a conclusion. Can you conclude that the mean lifetime of Brand A tires is greater than that of Brand B? Use H 0 : d = 0, H 1: d > 0 to state a conclusion. Use the method. A) Do not reject H 0 .

= 0.01 level of significance and the critical value B) Reject H 0 .

19) A computer system administrator notices that computer running a particular operating

19)

system seem to freeze up more often as the installation of the operating system ages. She measure the time (in minutes) before freeze-up for 7 computers one month after installation. The results are as follows. One month:

207.4 244.4 Seven months: 84.3 246.2

233.1 215.9 235.1 225.6 245.3 53.2 127.3 201.3 174.2 149.4 156.4 103.3

Can you conclude that the time to freeze-up is more variable in the seventh month than in the first month after installation? Use the = 0.01 level of significance. A) No B) Yes 20) An article in the Archives of Internal Medicine reported that in a sample of 242 men, 69

had elevated total cholesterol levels (more than 200 milligrams per deciliter). In a sample of 229 women, 44 had elevated cholesterol levels. Can you conclude that the proportion of people with elevated cholesterol levels differs between men and women? Use the = 0.05 level of significance and the critical value method. A) Do not reject H 0 . B) Reject H 0 .

20)

21) Find f

0.05

A) 3.01

21)

for F 8,18. B) 2.51

C) 2.04

D) 2.58

22) Medical researchers performed a comparison of two drugs, clopidogrel and ticagrelor,

22)

which are designed to reduce the risk of heart attack or stroke in coronary patients. A total of 6678 patients were given clopidogrel, and 6740 were given ticagrelor. Of the clopidogrel patients, 677 suffered a heart attack or stroke within one year, and of the ticagrelor patients, 579 suffered a heart attack or stroke. Can you conclude that the proportion of patients suffering a heart attack or stroke is less for ticagrelor? Use the = 0.01 level of significance and the critical value method. A) Reject H 0 . B) Do not reject H 0 . 23) King Tut was an ancient Egyptian ruler whose tomb was discovered and opened in 1923.

23)

Legend has it that the archaeologists who opened the tomb were subject to a "mummy’s curse," which would shorten their life spans. A team of scientists conducted an investigation of the mummy’s curse. They reported that the 25 people exposed to the curse had a mean life span of 70.2 years with a standard deviation of 12.3 years, while a sample of 11 Westerners in Egypt at the time who were not exposed to the curse had a mean life span of 75.3 years with a standard deviation of 13.3 years. Assume that the populations are approximately normal. Can you conclude that the mean life span of those exposed to the mummy’s curse is less than the mean of those not exposed? Use the = 0.05 level of significance and the critical value method. A) Do not reject H 0 . B) Reject H 0 . 24) A method of analyzing digital music files to determine the key in which the music was

24)

written was tested to determine its accuracy. In a sample of 299 pop music selections, the key was correctly identified in 250 of them. In a sample of 340 new age selections, the key was correctly identified in 297 of them. Can you conclude that the method is more accurate for new age music than for pop music? Use the = 0.05 level of significance and the critical value method. A) Reject H 0 . B) Do not reject H 0 . 25) Two types of thread are being considered for use in personal flotation devices. Breaking

strengths, in newtons, of ten threads of each type were measured, with the following results. Type A: 43 52 52 60 49 52 39 52 56 54 Type B: 49 45 49 56 52 45 47 56 56 41 Can you conclude that the standard deviations of the breaking strength differ between the two types? Use the = 0.05 level of significance. A) Yes B) No 8

25)

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. 26) In an experiment to determine whether there is a systematic difference between

26)

the weights obtained with two different mass balances, six specimens were weighed, in grams, on each balance. The following data were obtained: Specimen

1 2 3 4 5 6

5.57 7.78 12.30 6.58 11.57 14.11

5.57 7.79 12.31 6.57 11.56 14.11

Can you conclude that the mean weight differs between the two balances? i). State the null and alternative hypotheses. ii). Compute the test statistic. iii). State a conclusion using the = 0.02 level of significance. 27) Are low-fat diets or low-carb diets more effective for weight loss? A sample of

70 subjects went on a low-carbohydrate diet for six months. At the end of that time, the sample mean weight loss was 10.5 pounds with a sample standard deviation of 7.09 pounds. A second sample of 76 subjects went on a low-fat diet. Their sample mean weight loss was 18.0 with a standard deviation of 7.26. Can you conclude that the mean weight loss differed between the two diets? Use the = 0.05 level. i). State the appropriate null and alternate hypotheses. ii). Compute the test statistic. iii). How many degrees of freedom are there, using the simple method? iv). Do you reject H 0? State a conclusion.

27)

28) The football coach at State University wishes to determine if there is a decrease

28)

in offensive production between the first half and the second half of his team's recent games. The table below shows the first-half and second-half offensive production (measured in total yards gained per half) for the past six games. Game First half yards Second half yards

94 97

75 71

66 44

101 100

75 60

89 85

Can you conclude that the mean offensive production in the first half differed from that of the second half? i). State the null and alternative hypotheses. ii). Compute the test statistic. iii). State a conclusion using the = 0.05 level of significance. MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 29) The following MINITAB output display presents the results of a hypothesis test for the

difference 1 - 2 between two population means. Two-sample T for X1 vs X2 N Mean A 9 97.095 B 11 84.313

StDev 27.559 25.312

SE Mean 9.186 7.632

Difference = mu(X1) - mu(X2) Estimate for difference: 12.782 95% CI for difference: (-10.626, 36.190) T-Test of difference = 0 (vs not =) : T-Value = 1.070255 P-Value = 0.299465 DF = 17 What is the alternate hypothesis? A) 1 < 2 B) 1 > 2

C) 1

D) 1 = 2

29)

30) Following is a sample of five matched pairs.

Sample 1 Sample 2

26 19

24 19

17 16

30)

31 18

15 19

Let 1 and 2 represent the population means and let d = 1 – 2 . A test will be made of the hypotheses H 0 : d = 0 versus H 1 : d > 0. Compute the test statistic. A) 1.968

B) 3.893

C) 1.54

D) 0.689

31) In a random sample of 320 cars driven at low altitudes, 47 of them exceeded a standard

31)

of 10 grams of particulate pollution per gallon of fuel consumed. In an independent random sample of 95 cars driven at high altitudes, 21 of them exceeded the standard. Compute the test statistic for testing if the proportion of high-altitude vehicles exceeding the standard is greater than the proportion of low-altitude vehicles exceeding the standard. A) -3.52 B) -0.11 C) 1.72 D) -1.72 32) The following display from a TI-84 Plus calculator presents the results of a hypothesis

test for the difference between two means. The sample sizes are n1 = 9 and n2 = 9.

1> 2 t = -2.169049 p = 0.022745 df = 15.481009 x1 = 110.156 x2 = 135.341

What is the P-value? A) 0.977255

B) -2.169049

C) 15.481009

D) 0.022745

32)

33) The following display from a TI-84 Plus calculator presents the results of a hypothesis

33)

test for the difference between two proportions. The sample sizes are n1 = 92 and n2 = 77.

p1 > p2 z = -0.240826 p = 0.404845 ^

p1 = 0.358696 ^

p2 = 0.376623 ^

p = 0.366864

What is the P-value? A) 0.404845

B) 0.366864

C) -0.240826

D) 0.358696

34) In a test for the difference between two proportions, the sample sizes were n1 = 86 and

34)

n2 = 100, and the numbers of events were x1 = 53 and x2 = 63. A test is made of the hypothesis H 0: p1 = p2 versus H 1 : p1 Can you reject H 0 rejected at the

p2 .

= 0.01 level?

A) No

B) Yes

35) The following display from a TI-84 Plus calculator presents the results of a hypothesis

test for the difference between two means. The sample sizes are n1 = 13 and n2 = 14.

1> 2 t = 3.163775 p = 0.99797 df = 24.996042 x1 = 68.115 x2 = 38.714

Can you reject H 0 rejected at the

= 0.10 level?

A) No

B) Yes

35)

36) The football coach at State University wishes to determine if there is a change in

36)

offensive production between the first half and the second half of his team's recent games. The table below shows the first-half and second-half offensive production (measured in total yards gained per half) for the past six games. Game First half yards Second half yards

98 73

85 51

90 76

106 95

92 65

105 67

State the null and alternative hypotheses. A) H 0 : d = 0, H 1 : d = 24.8 C) H 0 : d = 0, H 1 d

B) H 0 : d = 0, H 1 : d < 0 D) H 0 : d = 0, H 1 : d > 0

37) The following MINITAB output display presents the results of a hypothesis test on the

37)

difference between two proportions. Test and CI for Two Proportions: P1, P2 Variable P1 P2

X 47 34

N 86 97

Sample P 0.546512 0.350515

Difference = p(P1) = p(P2) Estimate for difference: 0.195997 95% CI for difference: (0.051806, 0.340188) T-Test of difference = 0 (vs not = 0): Z = 2.664204 P-Value = 0.007717 What is the P-value? A) 0.007717

B) 2.664204

C) 0.44262295

D) 0.546512

38) Four null hypotheses were tested, and the P-values were:

38)

Hypothesis 1 2 3 4 P-value 0.012 0.047 0.016 0.012 Which hypotheses, if any, can be rejected at the = 0.05 level? A) None of them B) All of them C) 3, 4

D) 1, 4

39) A test was made of H 0 : 1 = 2 versus H 1 : 1 < 2. The sample means were x1 = 9 and

39)

x2 = 11, the sample standard deviations were s1 = 3 and s2 = 6, and the sample sizes were n1 = 16 and n2 = 12. Is H 0 rejected at the 0.05 level? (Hint: First compute the value of the test statistic.) A) Yes

B) No

40) In an experiment to determine whether there is a systematic difference between the

40)

weights obtained with two different mass balances, six specimens were weighed, in grams, on each balance. The following data were obtained: Specimen

1 2 3 4 5 6

6.05 8.00 13.45 7.47 6.53 14.38

6.01 8.02 13.43 7.48 6.52 14.38

State a conclusion using the = 0.05 level of significance. A) Reject H 0. The mean difference appears to differ from zero. B) Do not reject H 0. There is insufficient evidence to conclude that the mean

difference differs from zero. 41) An automobile manufacturer wishes to test that claim that synthetic motor oil can

improve gas mileage (in miles per gallon, or mpg). The table below shows the gas mileages, in mpg, of six cars that used synthetic motor oil. The table also shows the gas mileages in mpg of six cars that were using conventional motor oil (the controls). Synthetic: Control:

28 24

25 27

27 28

27 25

26 25

27 26

Can you conclude that the mean gas mileage for cars using synthetic motor oil is more than the mean for the controls? Use the = 0.05 level of significance. A) Yes B) No

41)

42) The following MINITAB output display presents the results of a hypothesis test on the

42)

difference between two proportions. Test and CI for Two Proportions: P1, P2 Variable P1 P2

X 47 41

N 83 99

Sample P 0.56626506 0.41414141

Difference = p(P1) = p(P2) Estimate for difference: 0.15212365 95% CI for difference: (0.00635336, 0.29789393) T-Test of difference = 0 (vs not = 0): Z = 2.04542613 Can you reject H 0 rejected at the

P-Value = 0.04081273

= 0.05 level?

A) No

B) Yes

43) A garden seed wholesaler wishes to test the claim that tomato seeds germinate faster

43)

when each individual seed is "pelletized" within a coating of corn starch. The table below shows the germination times, in days, of six pelletized seeds. The table also shows the germination times in days of six un-coated seeds (the controls). Pelletized: Control:

7 8

7 13

7 8

8 7

8 11

7 10

Can you conclude that the mean germination time for pelletized seeds is less than the mean for the un-pelletized seeds? Use the = 0.05 level of significance. A) No B) Yes 44) Five null hypotheses were tested, and the P-values were:

Hypothesis 1 P-value 0.017

2 0.023

3 0.006

4 0.024

5 0.005

Which hypotheses, if any, can be rejected at the = 0.05 level? A) 1, 2, 4 B) all of them C) none of them

44)

D) 3, 5

45) The football coach at State University wishes to determine if there is a decrease in

45)

142 134

143 116

85 66

84 84

138 122

71 65

Compute the test statistic. A) 2.881 B) 3.165

C) 1.288

D) 9.895

for F 12,4 46) Find the critical value f 0.01 A) 27.13

46)

B) 14.37

C) 43.52

D) 20.70

47) The following MINITAB output display presents the results of a hypothesis test on the

difference between two proportions. Test and CI for Two Proportions: P1, P2 Variable P1 P2

X 35 57

N 74 106

Sample P 0.472973 0.537736

Difference = p(P1) = p(P2) Estimate for difference: -0.064763 95% CI for difference: (-0.213181, 0.083655) T-Test of difference = 0 (vs not = 0): Z = -0.855257 P-Value = 0.392409 Is this a left-tailed test, a right-tailed test, or a two tailed test? A) Two-tailed test B) Right-tailed test

C) Left-tailed test

47)

48) The following display from a TI-84 Plus calculator presents the results of a hypothesis

48)

test for the difference between two means. The sample sizes are n1 = 7 and n2 = 12.

1> 2 t = -0.917205 p = 0.189353 df = 10.791309 x1 = 146.729 x2 = 157.769

How many degrees of freedom did the calculator use? A) 10.791309 B) 0.189353 C) 11.791309

D) -0.917205

49) The bowling scores of a professional bowler during a two-day tournament are shown

49)

below. Day 1 268 257

239 241

261 258

Day 2 249 231

273 271

256 250

223 228

284 224

292 210

241 268

Can you conclude that the variability of the scores is greater on the second day than on the first day? Use the = 0.05 level of significance. A) No B) Yes 50) A study reported that in a sample of 110 people who watch television news, 34 had

elevated diastolic blood pressure levels (in millimeters of mercury, or mmHg). In a sample of 78 people who do not watch television news, 13 had elevated diastolic blood pressure levels. Can you conclude that the proportion of people with elevated diastolic blood pressure levels differs between news-watchers and those who do not watch news? Use the = 0.05 level of significance. A) No B) Yes

50)

51) In a random sample of 380 cars driven at low altitudes, 48 of them exceeded a standard

51)

of 10 grams of particulate pollution per gallon of fuel consumed. In an independent random sample of 90 cars driven at high altitudes, 20 of them exceeded the standard. Can you conclude that the proportion of high-altitude vehicles exceeding the standard is greater than the proportion of low-altitude vehicles exceeding the standard at an = 0.1 level of significance? A) Yes B) No 52) A broth used to manufacture a pharmaceutical product has its sugar content, in

52)

milligrams per milliliter, measured several times on two successive days.The results are shown below. Day 1 3.9 7.4

4.3 3.3

6.5 3.7

Day 2 6.5 4.4

4.3 4.0

3.4 2.5

9.7 7.3

8.8 6.5

6.9 7.4

0.4 8.9

Can you conclude that the variability of the process is greater on the second day than on the first day? Use the = 0.01 level of significance. A) No B) Yes 53) A test was made of H 0 : 1 = 2 versus H 1 : 1 < 2. The sample means were x1 = 8 and

53)

x2 = 9, the sample standard deviations were s1 = 5 and s2 = 6, and the sample sizes were n1 = 15 and n2 = 11. How many degrees of freedom are there for the test statistic, using the simple method? A) 12 B) 10 C) 7 D) 11 54) A study reported that in a sample of 89 men, 29 had elevated total cholesterol levels

(more than 200 milligrams per deciliter). In a sample of 100 women, 28 had elevated cholesterol levels. Can you conclude that the proportion of people with elevated cholesterol levels differs between men and women? Use the = 0.05 level of significance. A) No B) Yes

54)

55) In an experiment to determine whether there is a systematic difference between the

55)

weights obtained with two different mass balances, six specimens were weighed, in grams, on each balance. The following data were obtained: Specimen

1 2 3 4 5 6

12.09 8.31 11.72 11.79 6.08 8.53

12.09 8.27 11.75 11.74 6.06 8.54

State the null and alternate hypotheses. A) H 0 : d = 0, H 1 : d = 0.012

B) H 0 : d = 0, H 1 : d

C) H 0 : d > 0, H 1 : d < 0

D) H 0 : d = 0, H 1 : d < 0

56) The following MINITAB output display presents the results of a hypothesis test for the

difference 1 - 2 between two population means. Two-sample T for X1 vs X2 N Mean A 7 145.411 B 14 132.964

StDev 24.669 25.604

SE Mean 9.324 6.843

Difference = mu(X1) - mu(X2) Estimate for difference: 12.447 95% CI for difference: (-10.222, 35.116) T-Test of difference = 0 (vs not =) : T-Value = 1.076209 P-Value = 0.301402 DF = 13 How many degrees of freedom are there for the test statistic? A) 0.301402 B) 13 C) 12

D) 12.447

56)

57) Following is a sample of five matched pairs.

Sample 1 Sample 2

20 15

21 20

24 17

20 22

57)

21 21

Let 1 and 2 represent the population means and let d = 1 - 2. A test will be made of the hypotheses H 0 : d = 0 versus H 1 : d > 0. Can you reject H 0 at the = 0.05 level of significance? A) No

B) Yes

58) In an experiment to determine whether there is a systematic difference between the

weights obtained with two different mass balances, six specimens were weighed, in grams, on each balance. The following data were obtained: Specimen

1 2 3 4 5 6

7.35 10.83 14.12 9.85 10.86 13.44

7.33 10.81 14.10 9.87 10.85 13.43

Compute the test statistic. A) 0.645 B) 0.197

C) 1.443

D) 1.581

58)

59) The following display from a TI-84 Plus calculator presents the results of a hypothesis

59)

test for the difference between two proportions. The sample sizes are n1 = 81 and n2 = 110.

p1 > p2 z = -0.05807911 p = 0.47684274 ^

p1 = 0.60493827 ^

p2 = 0.60909091 ^

p = 0.60732984

Can you reject H 0 rejected at the

= 0.05 level?

A) Yes

B) No

60) An F-test with 6 degrees of freedom in the numerator and 8 degrees of freedom in the

60)

denominator produced a test statistic whose value was 4.03. The null and alternate hypotheses were H 0 : 1 = 2 versus H 1: 1 < 2 . Do you reject H 0 at the

= 0.05 level?

A) No

B) Yes

61) The concentration of hexane (a common solvent) was measured in units of micrograms

per liter for a simple random sample of thirteen specimens of untreated ground water taken near a municipal landfill. The sample mean was 672.1 with a sample standard deviation of 4.2. Ten specimens of treated ground water had an average hexane concentration of 672.0 with a standard deviation of 3.4. It is reasonable to assume that both samples come from populations that are approximately normal. Can you conclude that the mean hexane concentration is less in treated water than in untreated water? Use the = 0.02 level of significance. A) No B) Yes

61)

62) The football coach at State University wishes to determine if there is a decrease in

62)

149 143

111 110

90 80

108 101

132 142

126 103

State a conclusion using the = 0.10 level of significance. A) Reject H 0 . The mean offensive production appears to decrease from the first

half to the second half. B) Do not reject H 0 . There is insufficient evidence to conclude that the mean offensive production decreases from the first to the second half. 63) An amateur golfer wishes to determine if there is a difference between the drive

63)

distances of her two favorite drivers. (A driver is a specialized club for driving the golf ball down range.) She hits fourteen balls with driver A and 10 balls with driver B. The drive distances (in yards) for the trials are show below. Driver A 254 276 269 276 287 249 297 262 279 265 266 263 244 264 Driver B 262 262 231 282 252 252 221 235 226 247 Assume that the populations are approximately normal. Can you conclude that there is a difference in the mean drive distances for the two drivers? Use the = 0.05 level of significance. A) Yes B) No 64) In a test for the difference between two proportions, the sample sizes were n1 = 73 and

n2 = 89, and the numbers of events were x1 = 26 and x2 = 55. A test is made of the hypothesis H 0: p1 = p2 versus H 1 : p1

p2 .

Compute the value of the test statistic. A) -3.32 B) -3.07

C) -3.44

D) -3.22

64)

65) In an agricultural experiment, the effects of two fertilizers on the production of oranges

65)

were measured. Fourteen randomly selected plots of land were treated with fertilizer A, and 10 randomly selected plots were treated with fertilizer B. The number of pounds of harvested fruit was measured from each plot. Following are the results. Fertilizer A 484 530 522 497 471 504 497 534 461 522 473 520 467 517 Fertilizer B 447 454 461 445 475 489 470 497 484 548 Assume that the populations are approximately normal. Can you conclude that there is a difference in the mean yields for the two types of fertilizer? Use the = 0.05 level of significance. A) No B) Yes 66) The following MINITAB output display presents the results of a hypothesis test for the

66)

difference 1 - 2 between two population means. Two-sample T for X1 vs X2 N Mean A 12 66.021 B 8 40.649

StDev 22.014 27.337

SE Mean 6.355 9.665

Difference = mu(X1) - mu(X2) Estimate for difference: 25.372 95% CI for difference: (2.700, 48.044) T-Test of difference = 0 (vs not =) : T-Value = 2.193456 P-Value = 0.04706 DF = 13 Can you reject H 0 rejected at the

= 0.01 level?

A) Yes

B) No

67) A test was made of H 0 : 1 = 2 versus H 1 : 1 < 2. The sample means were x1 = 12 and

x2 = 10, the sample standard deviations were s1 = 5 and s2 = 6, and the sample sizes were n1 = 18 and n2 = 14. Compute the value of the test statistic. A) 1.449 B) 0.256

C) 1.005

D) 2.38

67)

68) The following display from a TI-84 Plus calculator presents the results of a hypothesis

68)

test for the difference between two proportions. The sample sizes are n1 = 99 and n2 = 94.

p1 > p2 z = -1.91804 p = 0.027553 ^

p1 = 0.383838 ^

p2 = 0.521277 ^

p = 0.450777

Is this a left-tailed test, a right-tailed test, or a two-tailed test? A) Two-tailed test B) Right-tailed test

C) Left-tailed test

69) A sociologist studies a sample of college students to determine whether there are

69)

differences in the attitudes and behaviors of male and female students. The survey contains 25 questions. For one question, which asks how much time students spend studying each week, the difference between males and females is statistically significant with a P-value of 0.005. On all the other questions, the differences are not statistically significant. What P-value would be needed to conclude at the = 0.05 level that the time spent studying differs between male and female students after applying the Bonferroni correction? A) 0.0002 B) 0.1250 C) 0.0004 D) 0.2500 TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 70) The F-test for two standard deviations is very sensitive to the normality assumption.

70)

71) The test statistic F is never greater than 1.

71)

Answer Key Testname: C11

1) A 2) A 3) B 4) B 5) D 6) A 7) B 8) A 9) A 10) B 11) B 12) B 13) A 14) C 15) D 16) B 17) B 18) A 19) B 20) B 21) B 22) A 23) A 24) B 25) B 26) i). H 0 : d = 0, H 1 : d

ii). 0 iii). Do not reject H 0. There is insufficient evidence to conclude that the meandifference differs from zero. 27) i). H 0 : 1 = 2 versus H 1 : 1

ii). -6.312 iii). 69 iv). Yes. There appears to be a difference in the mean weight losses. 28) i). H 0 : d = 0, H 1 : d > 0

ii). 1.865 iii). Do not reject H 0 . There is insufficient evidence to conclude that the mean offensive production decreases from the first to the second half. 29) C 30) C 31) D 32) D 33) A 34) A 35) A 36) C 37) A 38) D 25

Answer Key Testname: C11

39) B 40) B 41) B 42) B 43) B 44) D 45) B 46) B 47) A 48) A 49) B 50) B 51) A 52) A 53) B 54) A 55) B 56) B 57) A 58) D 59) B 60) B 61) A 62) B 63) A 64) A 65) A 66) B 67) C 68) B 69) C 70) TRUE 71) FALSE

Exam Name___________________________________

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Find the area to the right of 59.892 under the chi-square distribution with 37 degrees of

freedom. A) 0.10

B) 0.005

C) 0.01

D) 0.99

2) Find the area to the right of 21.995 under the chi-square distribution with 8 degrees of

freedom. A) 0.995 3) Find the

B) 0.10

B) 43.195

C) 40.113

D) 40.113 4)

= 0.10 critical value for the chi-square distribution with 26 degrees of

freedom. A) 10.085

B) 23.542

C) 24.769

D) 27.587

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. 5) For the given table of observed frequencies:

A B C

1 64 93 49

2 67 88 95

3 55 88 95

i). Compute the row totals, the column totals, and the grand total. ii). Construct the corresponding table of expected values. iii). Compute the value of the chi-square test statistic. iv). Perform a test for independence, using the = 0.01 level of significance.

D) 0.005

= 0.05 critical value for the chi-square distribution with 41 degrees of

freedom. A) 38.885 4) Find the

C) 0.01

6) The number of visits to a certain web site were counted each day of a particular

week. The results are given in the following table. Day Sunday Monday Tuesday Wednesday Thursday Friday Saturday

Number of Visits 132 122 117 117 125 135 140

Test the hypothesis that the web site visits are equally likely to occur on any day of the week. Use the = 0.05 level of significance. 7) The following table presents the numbers of customers who - after 2 weeks of use

- were satisfied or dissatisfied with their newly-purchased computers.

Satisfied Dissatisfied

Brand A 26 5

Brand B 37 14

Brand C 37 9

Brand D 43 14

Can you conclude that the satisfaction rate is related to the brand of computer? Use the = 0.01 level of significance.

8) The number of drunk-driving arrests were counted each month by the Millville

police department. The results are given in the following table. Month

Number of Drunk-Driving Arrests January 21 February 22 March 12 April 12 May 13 June 14 July 13 August 13 September 15 October 10 November 10 December 24 Test the hypothesis that drunk-driving arrests are equally likely to occur in any month. Use the = 0.05 level of significance. 9) The following table presents the numbers of cucumber seeds, by brand, that

germinated or failed to germinate 14 days after planting.

Germinated Failed to Germinate

Brand A 34 6

Brand B 31 2

Brand C 37 5

Brand D 29 13

Can you conclude that the germination rate is related to the brand of seed? Use the = 0.05 level of significance.

10) A psychology instructor gave a five-question true-false quiz to her class of 175

10)

students. The results were as follows. Number Correct Observed

0 1

1 31

2 54

3 53

4 36

5 0

The instructor thinks that the students may have answered the questions by guessing, so that the probability that any given answer is correct is 0.5. Under the null hypothesis, the number of correct answers has a binomial distribution with 5 trials and success probability 0.5. Perform a chi-square test of this hypothesis. Can you reject H 0 at the

= 0.01

level? 11) A sample of 192 university students who recently moved off-campus were polled

to see whether they agree that off-campus living is preferable to on-campus living. In addition, each was asked how many people live in their current off-campus residence. The results are summarized in the following contingency table.

Agree No Opinion Disagree

1 22 12 11

2 34 19 24

3 39 18 13

11)

12) A biology professor claims that, on the average, 20% of her students get a grade

12)

of A, 30% get a B, 25% get a C, 10% get a D, and 15% get an F. The grades of a random sample of 121 students were recorded. The following table presents the results. Grade Observed

1 9

2 30

3 33

4 28

5 21

i). Compute the expected frequencies. ii). What is the value of 2 ? iii). How many degrees of freedom are there? iv). Test the hypothesis that the grades follow the distribution claimed by the professor. Use the = 0.05 level of significance. 13) Following are observed frequencies. The null hypothesis is H 0 : p1 = 0.3,

13)

p2 = 0.3, p3 = 0.2, p4 = 0.1, p5 = 0.1. Category Observed

1 29

2 42

3 15

4 13

5 3

i). Compute the expected frequencies. ii). Compute the value of 2 . iii). How many degrees of freedom are there? iv). Test the hypothesis that the distribution of the observed frequencies is as given by the null hypothesis. Use the = 0.01 level of significance. MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 14) Find the

14)

15) Following are observed frequencies. The null hypothesis is H 0 : p1 = 0.4, p2 = 0.2,

15)

= 0.01 critical value for the chi-square statistic with 5 degrees of freedom. A) 13.277 B) 15.086 C) 16.750 D) 0.544

p3 = 0.15, p4 = 0.1, p5 = 0.15. Category Observed

1 38

2 26

3 18

4 4

5 13

Compute the expected frequencies. A) 39.6, 19.8, 14.85, 9.9, 14.85 C) 0.384, 0.263, 0.182, 0.04, 0.131

B) 19.8, 19.8, 19.8, 19.8, 19.8 D) 38, 26, 18, 4, 13

16) The following table presents the numbers of cucumber seeds, by brand, that germinated

16)

or failed to germinate 14 days after planting.

Germinated Failed to Germinate

Brand A 44 10

Brand B 33 9

Brand C 35 2

Brand D 31 17

Can you conclude that the germination rate is related to the brand of seed? Use the = 0.01 level of significance. A) Do not reject H 0 . There is insufficient evidence to conclude that the germination

rate differs among the seed brands. B) Reject H 0 . It appears that the germination rates differ among the seed brands. 17) For the given table of observed frequencies, perform a test for independence, using the

17)

= 0.01 level of significance.

A B C

1 69 91 42

2 64 98 84

3 67 88 86

A) Do not reject H 0 .

B) Reject H 0 .

18) A sample of 149 university students who recently moved off-campus were polled to see

whether they agree that off-campus living is preferable to on-campus living. In addition, each was asked how many people live in their current off-campus residence. The results are summarized in the following contingency table.

Agree No Opinion Disagree

1 25 8 11

2 17 12 18

3 34 15 6

Perform a test for independence, using the = 0.01 level of significance. What do you conclude? A) Do not reject H 0 . There is insufficient evidence to conclude that the survey

responses and the number of roommates are dependent. B) Reject H 0 . It appears that the survey responses and the number of roommates are dependent.

18)

19) A biology professor claims that, on the average, 10% of her students get a grade of A,

19)

30% get a B, 35% get a C, 10% get a D, and 15% get an F. The grades of a random sample of 113 students were recorded. The following table presents the results. Grade Observed

1 3

2 34

3 38

4 12

5 26

Compute the expected frequencies. A) 22.6, 22.6, 22.6, 22.6, 22.6 C) 11.3, 33.9, 39.55, 11.3, 16.95

B) 3, 34, 38, 12, 26 D) 0.027, 0.301, 0.336, 0.106, 0.23

20) The following table presents the numbers of customers who - after 2 weeks of use - were

20)

satisfied or dissatisfied with their newly-purchased computers.

Satisfied Dissatisfied

Brand A 38 3

Brand B 26 9

Brand C 21 13

Brand D 44 9

Can you conclude that the satisfaction rate is related to the brand of computer? Use the = 0.05 level of significance. A) Do not reject H 0 . There is insufficient evidence to conclude that the satisfaction

rate differs among the computer brands. B) Reject H 0 . It appears that the satisfaction rates differ among the computer brands. 21) Following are observed frequencies. The null hypothesis is H 0 : p1 = 0.3, p2 = 0.3,

p3 = 0.2, p4 = 0.15, p5 = 0.05. Category Observed

1 41

2 44

3 6

4 25

5 2

Compute the value of 2 . A) 21.689 B) 13.277

C) 15.086

D) 23.138

21)

22) A psychology instructor gave a five-question true-false quiz to her class of 201 students.

22)

The results were as follows. Number Correct Observed

0 10

1 40

2 56

3 64

4 25

5 6

= 0.01 level?

B) No

23) Following is a set of observed and expected frequencies:

Observed Expected

10 10

20 10

26 20

30 20

19 15

Test the hypothesis that the distribution of the observed frequencies is as given by the expected frequencies. Use the = 0.01 level of significance. A) Reject H 0 . B) Do not reject H 0 .

23)

24) The number of drunk-driving arrests were counted each month by the Millville police

24)

department. The results are given in the following table. Month

Number of Drunk-Driving Arrests January 24 February 21 March 13 April 11 May 13 June 11 July 10 August 13 September 14 October 14 November 13 December 25 Test the hypothesis that drunk-driving arrests are equally likely to occur in any month. Use the = 0.05 level of significance. A) Do not reject H 0 . The arrests may be equally likely. B) Reject H 0 . The arrests do not appear to be equally likely. 25) Find the area to the right of 24.725 under the chi-square distribution with 11 degrees of

freedom. A) 0.99

B) 0.015

C) 0.005

D) 0.01

26) A biology professor claims that, on the average, 15% of her students get a grade of A,

25% get a B, 35% get a C, 10% get a D, and 15% get an F. The grades of a random sample of 109 students were recorded. The following table presents the results. Grade Observed

1 4

2 31

3 42

4 13

5 19

What is the value of 2? A) 9.488 B) 11.143

C) 11.067

25)

D) 12.317

26)

27) For the following observed and expected frequencies, compute the value of 2.

Observed Expected

3 5

13 10

A) 5.709

23 25

19 20

27)

7 10

B) 9.488

C) 2.810

D) 11.070

28) Following are observed frequencies. The null hypothesis is H 0 : p1 = 0.35, p2 = 0.3,

28)

p3 = 0.1, p4 = 0.15, p5 = 0.1. Category Observed

1 51

2 32

3 11

4 13

5 16

Test the hypothesis that the distribution of the observed frequencies is as given by the null hypothesis. Use the = 0.01 level of significance. A) Reject H 0 . B) Do not reject H 0 . 29) A biology professor claims that, on the average, 15% of her students get a grade of A,

30% get a B, 30% get a C, 10% get a D, and 15% get an F. The grades of a random sample of 105 students were recorded. The following table presents the results. Grade Observed

1 17

2 39

3 26

4 5

5 18

Test the hypothesis that the grades follow the distribution claimed by the professor. Use the = 0.01 level of significance. A) Reject H 0 . B) Do not reject H 0 .

29)

30) The number of visits to a certain web site were counted each day of a particular week.

The results are given in the following table. Day Sunday Monday Tuesday Wednesday Thursday Friday Saturday

Number of Visits 134 111 125 123 122 150 150

Test the hypothesis that web site visits are equally likely to occur on any day of the week. Use the = 0.05 level of significance. A) Reject H 0 . The visits do not appear to be equally likely. B) Do not reject H 0 . The visits may be equally likely.

30)

Answer Key Testname: C12

1) C 2) D 3) D 4) C 5) i).

A B C Column Total

1 64 93 49 206

2 67 88 95 250

3 55 88 95 238

Row Total 186 269 239 694

ii). Expected Values:

A B C

1 55.210375 79.847262 70.942363

2 67.002882 96.902017 86.095101

3 63.786744 92.25072 81.962536

iii). 2 = 15.571547 iv.)

2 = 13.277; Reject H 0. crit

6) Expected frequency for each day: 126.857143 2 = 3.837838

2 = 12.591587 crit

Do not reject H 0 The visits may be equally likely.

Answer Key Testname: C12

7) Row and column totals:

Brand A Satisfied 26 Dissatisfied 5 Column Total 31

Brand B 37 14 51

Brand C 37 9 46

Brand D 43 14 57

Row Total 143 42 185

Expected Values:

Satisfied Dissatisfied 2 = 1.788862;

Brand A 23.962162 7.037838

Brand B 39.421622 11.578378

Brand C 35.556757 10.443243

Brand D 44.059459 12.940541

2 = 11.345 crit

Do not reject H 0 . There is insufficient evidence to conclude that the satisfaction rate differs among the computer brands. 8) Expected frequency for each month: 15.333333 2 = 14.391304

2 = 19.675138 crit

Do not reject H 0 The arrests may be equally likely. 9) Row and column totals:

Brand A Germinated 34 Failed to Germinate 6 Column Total 40

Brand B 31 2 33

Brand C 37 5 42

Brand D 29 13 42

Row Total 131 26 157

Expected Values:

Germinated Failed to Germinate 2 = 9.657887;

Brand A 33.375796 6.624204

Brand B 27.535032 5.464968

Brand C 35.044586 6.955414

Brand D 35.044586 6.955414

2 = 7.815 crit

Reject H 0 . It appears that the germination rates differ among the seed brands.

Answer Key Testname: C12

10) Expected frequencies: 5.42875, 27.34375, 54.6875, 54.6875, 27.34375, 5.42875 2 = 12.410286

2 = 15.086 crit

No 11) i). Agree No Opinion Disagree Column Total

1 22 12 11 45

2 34 19 24 77

3 39 18 13 70

Row Total 95 49 48 192

ii). Expected Values:

Agree No Opinion Disagree

1 22.265625 11.484375 11.25

2 38.098958 19.651042 19.25

3 34.635417 17.864583 17.5

iii). 2 = 3.37469 iv.)

2 = 9.488; Do not reject H 0 . There is insufficient evidence to conclude crit

that the survey responses and number of roommates are dependent. 12) i). 24.2, 36.3, 30.25, 12.1, 18.15 ii). 32.231 iii). 4 iv). Reject H 0 . 13) i). 30.6, 30.36, 20.4, 10.2, 10.2

ii). 11.611 iii). 4 iv). Do not reject H 0 . 14) B 15) A 16) B 17) B 18) B 19) C 20) B 21) A 22) B 23) A 14

Answer Key Testname: C12

24) A 25) D 26) C 27) C 28) B 29) B 30) B

Exam Name___________________________________

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) For the following residual plot, determine whether the assumptions of the linear model

are satisfied. If they are not, specify which assumptions are violated.

A) No, the plot contains outliers. B) No, the plot exhibits an obvious curved pattern. C) Yes, The assumptions of the linear model are satisfied. D) No, the vertical spread varies. 2) For the following residual plot, determine whether the assumptions of the linear model

are satisfied. If they are not, specify which assumptions are violated.

A) No, the vertical spread varies. B) Yes, the assumptions of the linear model are satisfied. C) No, the plot contains outliers. D) No, the plot exhibits an obvious curved pattern.

3) For the following residual plot, determine whether the assumptions of the linear model

are satisfied. If they are not, specify which assumptions are violated.

A) No, the plot contains outliers. B) No, the vertical spread varies. C) No, the plot exhibits an obvious curved pattern. D) Yes, The assumptions of the linear model are satisfied. 4) Two people differ in age by 2.2 years. Their heights and weights are the same, and their

lung capacities are measured at the same pressure and temperature. By how much should we predict their lung capacities to differ? Use the figure below.

The regression equation is Lung capacity = -7.82 + 0.119 Height - 0.0246 Weight + 0.164 Age + 0.076 Pressure + 0.0202 Temperature Predictor Constant Height Weight Age Pressure Temperature

Coef -7.817 0.11927 -0.024627 0.16411 0.0764 0.02022

SE Coef 6.288 0.03292 0.008965 0.16411 0.0764 0.02022

T -1.24 3.62 -2.75 2.62 0.46 1.18

S = 0.214478

R-Sq = 88.0% R-Sq(adj) = 81.9%

P 0.242 0.005 0.021 0.025 0.652 0.266

Analysis of Variance Source Regression Residual Error Total A) 0.0445

DF 5 10 15

SS 3.35908 0.46001 3.81909

MS 0.67182 0.04600

B) 0.1641

C) 0.2624

F 14.60

D) 0.3610

P 0.003

5) Use the coefficients of the multiple regression equation in the figure below to predict the

lung capacity for a 11-year-old who is 57 inches tall and weighs 92 pounds, at a pressure of 30.9 inches and a temperature of 67 degrees.

The regression equation is Lung capacity = -7.82 + 0.119 Height - 0.0246 Weight + 0.164 Age + 0.076 Pressure + 0.0202 Temperature Predictor Constant Height Weight Age Pressure Temperature

Coef -7.817 0.11927 -0.024627 0.16411 0.0764 0.02022

SE Coef 6.288 0.03292 0.008965 0.16411 0.0764 0.02022

T -1.24 3.62 -2.75 2.62 0.46 1.18

S = 0.214478

R-Sq = 88.0% R-Sq(adj) = 81.9%

P 0.242 0.005 0.021 0.025 0.652 0.266

Analysis of Variance Source Regression Residual Error Total A) 0.882

DF 5 10 15

SS 3.35908 0.46001 3.81909

MS 0.67182 0.04600

B) 2.207

C) 2.236

F 14.60

D) 2.357

P 0.003

6) The following MINITAB output presents a multiple regression equation y = b0 +

b1x1 + b2 x2 + b3 x3 + b4 x4 .

The regression equation is Y = 5.5601 - 1.9908 X1 - 0.8440 X2 - 1.4960 X3 + 0.9992 X4 Predictor Constant X1 X2 X3 X4

Coef 5.5601 -1.9908 -0.8440 -1.4960 0.9992

S = 2.6494

R-Sq = 45.3% R-Sq(adj) = 37.7%

Analysis of Variance Source DF Regression 4 34 Residual Error 38 Total

SE Coef 0.8173 0.7657 0.6114 0.8265 0.7132

T 0.85230 3.41280 -2.95240 -0.85970 1.82550

SS 902.3 1091.7 1994.0

MS 225.6 32.1

P 0.3390 0.0040 0.0100 0.3410 0.0730

F 7.0280

P 0.003

It is desired to drop one of the explanatory variables. Which of the following is the most appropriate action? A) Drop x3, then see whether adjusted R 2 increases B) Drop x1, then see whether adjusted R 2 increases C) Drop x1, then see whether R 2 increases D) Drop x3, then see whether R 2 increases

7) For the following residual plot, determine whether the assumptions of the linear model

are satisfied. If they are not, specify which assumptions are violated.

A) No, the plot exhibits an obvious curved pattern. B) Yes, the assumptions of the linear model are satisfied. C) No, the vertical spread varies. D) No, the plot contains outliers. SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. 8) In a study of reaction times, the time to respond to a visual stimulus (x) and the

time to respond to an auditory stimulus (y) were recorded for each of 8 subjects. Times were measured in thousandths of a second. The results are presented in the following table. Visual 244 249 167 209 195 241 152 167

Auditory 250 248 246 240 242 248 237 239

i). Compute the least-squares regression line for predicting auditory response time (y) from visual response time (x). ii). Construct a 95% confidence interval for the slope of the least-squares regression line. iii). Test H 0 : 1 = 0 versus H 1 : 1 0. Use the = 0.05 level of significance.

9) The following MINITAB output presents a confidence interval for a mean

response and a prediction interval for an individual response.

New Obs 1

Fit 10.598

SE Fit 1.139

95.0% CI 95.0% PI (4.106, 17.090) (3.685, 17.511)

Values of Predictors for New Observations New Obs 1

X1 1.95

X2 1.30

X3 2.22

What is the 95% confidence interval for the mean response? 10) The following MINITAB output presents a confidence interval for a mean

response and a prediction interval for an individual response.

New Obs 1

Fit 8.395

SE Fit 1.172

95.0% CI 95.0% PI (2.336, 14.454) (1.861, 14.929)

Values of Predictors for New Observations New Obs 1

X1 2.38

X2 2.49

X3 1.86

What is the 95% prediction interval for the new observation?

10)

11) Use the given set of points to

11)

a). Compute b0 and b1 . ^

b). Compute the predicted value y for the given value of x. c). Compute the residual standard deviation se. 2

d). Compute the sum of squares for x, (x - x) . e). Find the critical value for a 95% confidence or prediction interval. f). Construct a 95% confidence interval for the mean response for the given value of x. g). Construct a 95% prediction interval for an individual response for the given value of x. x y

18 45

17 43

10 29

13 34

20 48

11 30

x = 16

12) The summary statistics for a certain set of points are: n = 12, se = 3.494, 2

(x - x) = 17.375, and b1 = 1.447. Assume the conditions of the linear model hold. A 95% confidence interval for 1 will be constructed. i). How many degrees of freedom are there for the critical value? ii). What is the critical value? iii). What is the margin of error? iv). Construct the 95% confidence interval.

12)

13) In a study of reaction times, the time to respond to a visual stimulus (x) and the

13)

Auditory 244 250 250 239 246 250 246 248

i). Compute a point estimate for the mean auditory response time for subjects with a visual response time of 184. ii). Construct a 95% confidence interval for the mean auditory response time for subjects with a visual response time of 184. iii). Predict the auditory response time for a particular subject whose visual response time of 184. iv). Construct a 95% prediction interval for the auditory response time for a particular subject whose visual response time is 184.

14) Use the given set of points to

14)

a). Compute b1 . b). Compute the residual standard deviation se. 2

c). Compute the sum of squares for x, (x - x) . d). Compute the standard error of b1 , sb . e). Find the critical value for a 99% confidence interval for 1 . f). Compute the margin of error for a 99% confidence interval for 1 . g). Construct a 99% confidence interval for 1 . h). Test the null hypothesis H 0 : 1 = 0 versus H 1 : 1 0. Use the of significance. x y

5 13

5 19

13 24

13 28

6 16

13 33

12 27

7 17

= 0.01 level

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. ^

15) The following MINITAB output presents a multiple regression equation y = b0 + b1 x1 +

15)

b 2 x2 + b 3 x3 + b 4 x4 .

The regression equation is Y = 6.0691 + 0.4227 X1 + 0.8321 X2 + 0.0113 X3 + 1.4144 X4 Predictor Constant X1 X2 X3 X4

Coef 6.0691 0.4227 0.8321 0.0113 1.4144

S = 2.8772

R-Sq = 43.3% R-Sq(adj) = 35.8%

Analysis of Variance Source DF Regression 4 35 Residual Error 39 Total

SE Coef 0.8094 0.6664 0.7976 0.7000 0.8055

T 1.0327 3.5619 -3.1177 1.9718 -0.9772

SS 642.7 840.9 1483.6

MS 160.7 24.0

P 0.350 0.003 0.008 0.071 0.348

F 6.6958

Let 3 be the coefficient X 3 . Test the hypothesis H0: 3 = 0 versus H1 : 3 the = 0.05 level. What do you conclude? A) Do not reject H 0 B) Reject H 0

P 0.003

0 at

16) Use the given set of points to compute the residual standard deviation se.

x 5 12 y 17 30 A) 1.8333

13 32

15 35

9 13 26 34 B) 66.0000

11 25

10 27 C) 1.7159

D) 8.0833

16)

17) In a study of reaction times, the time to respond to a visual stimulus (x) and the time to

17)

respond to an auditory stimulus (y) were recorded for each of 8 subjects. Times were measured in thousandths of a second. The results are presented in the following table. Visual 240 226 183 155 156 199 222 175

Auditory 247 245 244 243 239 244 247 243

Compute a point estimate for the mean auditory response time for subjects with a visual response time of 210. A) 244.00 B) 246.42 C) 243.68 D) 245.05 18) The summary statistics for a certain set of points are: n = 14, se = 8.717,

18)

(x - x) = 8.238, and b1 = 1.724. Assume the conditions of the linear model hold. A 95% confidence interval for 1 will be constructed. Test the null hypothesis H 0 : 1 = 0 versus H 0 : 1 > 0. Use the = 0.05 level of significance. A) Reject H 0 . B) Do not reject H 0 . 19) The summary statistics for a certain set of points are: n = 17, se = 2.880,

19)

(x - x) = 19.241, and b1 = 1.839. Assume the conditions of the linear model hold. A 95% confidence interval for 1 will be constructed. What is the margin of error? A) 1.391921 B) 1.399143

C) 41.002571

D) 1.146365

20) The following table lists values measured for 10 consecutive eruptions of the geyser Old

20)

Faithful in Yellowstone National Park. They are the duration, in minutes, of the eruption (x1), the dormant period before the eruption (x2 ), and the dormant period after the eruption (y). x1 x2 y 1.8 42 91 4.1 91 51 1.8 51 79 3.2 79 53 1.9 53 82 4.6 82 51 2.0 51 76 4.5 76 82 3.9 82 84 4.3 84 53 ^

Construct the multiple regression equation y = b0 + b1x1 + b2 x2 ^

B) y = 123.94 + 7.4321x1 - 1.1230x2

D) y = -1.18 + 7.25x1 + 112.79x2

A) y = -1.1230 + 7.4321x1 + 123.94x2

C) y = 112.79 + 7.25x1 - 1.18x2

21) Use the given set of points to test the null hypothesis H 0 : 1 = 0 versus H 1 : 1

the

= 0.05 level of significance. x 9 12 7 10 9 6 y 21 29 18 23 17 15 A) Do not reject H 0 .

15 34

10 25 B) Reject H 0 .

0. Use

21)

22) The following MINITAB output presents a 95% confidence interval for the mean ozone

22)

level on days when the relative humidity is 45%, and a 95% prediction interval for the ozone level on a particular day when the relative humidity is 45%. The units of ozone are parts per billion. Predicted Values for New Observations New Obs 1

Fit 44.57

SE Fit 1.6

95.0% CI (41.43, 47.71)

95.0% PI (31.19, 57.95)

Values of Predictors for New Observations New OBS 1

Humidity 45.0%

What is the 95% confidence interval for the mean ozone level for days when the relative humidity is 45%? A) (45, 95) B) (1.6, 44.57) C) (41.43, 47.71) D) (31.19, 57.95) 23) The following display from a TI-84 Plus calculator presents the results of a test of the

23)

null hypothesis H 0 : 1 = 0.

y = a+bx 0 and 0 t = 2.191024 p = 0.056156 df = 9 a = 2.527587

What is the P-value? A) 0.056156

B) 2.191024

C) 2.527587

D) 9

24) The summary statistics for a certain set of points are: n = 19, se = 3.503,

24)

(x - x) = 18.570, and b1 = 1.432. Assume the conditions of the linear model hold. A 95% confidence interval for 1 will be constructed. What is the critical value? A) 2.110 B) 1.740

C) 2.101

D) 1.734

25) For a sample of size 21, the following values were obtained: b0 = 4.73, b1 = 3.12,

25)

se = 4.84,

(x - x) = 208.77, and x = 4.55.

Construct a 99% confidence interval for the mean response when x = 3. A) (10.58, 17.60) B) (10.72, 17.46) C) (11.10, 17.08) D) (0, 17.08) 26) Use the given set of points to compute the residual standard deviation se.

x y

16 87

10 61

17 95

A) 11.833333

14 79

20 109

19 x = 17 104

B) 16

C) 4.833333

D) 1.322876

27) Use the given set of points to compute the margin of error for a 99% confidence interval

for 1 . x 13 13 y 33 27 A) 1.2795

9 28

10 27

6 12 16 28 B) 3.2356

15 29

A) (60.49, 70.67)

17 88

13 70

14 73

27)

5 18 C) 1.3855

D) 0.3452

28) Use the given set of points to construct a 95% confidence interval for the mean response

for the given value of x. x 10 19 15 y 56 97 83

26)

x = 12

B) (62.35, 68.81)

C) (63.10, 68.06)

D) (58.95, 72.21)

28)

29) In a study of reaction times, the time to respond to a visual stimulus (x) and the time to

29)

Auditory 247 250 244 249 247 238 247 242

Construct a 95% confidence interval for the mean auditory response time for subjects with a visual response time of 223. A) (245.76, 248.56) B) (243.34, 250.98) C) (245.4, 248.92) D) (242.35, 251.97) 30) The following MINITAB output presents a 95% confidence interval for the mean ozone

level on days when the relative humidity is 65%, and a 95% prediction interval for the ozone level on a particular day when the relative humidity is 65%. The units of ozone are parts per billion. Predicted Values for New Observations New Obs 1

Fit 43.98

SE Fit 1.3

95.0% CI (41.43, 46.53)

95.0% PI (30.74, 57.22)

Values of Predictors for New Observations New OBS 1

Humidity 65.0%

What is the point estimate for the mean ozone level for days when the relative humidity is 65%? A) 43.98 B) 1.3 C) 65.0 D) 41.43

30)

31) Use the given set of points to compute b0 and b1 .

x y

11 27

14 32

12 29

20 44

18 41

11 28

31)

x = 15

A) b0 = 0; b1 = 1.881818

B) b0 = 1.881818; b1 = 6.527273

C) b0 = 14.333333; b1 = 6.527273

D) b0 = 6.527273; b1 = 1.881818

32) In a study of reaction times, the time to respond to a visual stimulus (x) and the time to

respond to an auditory stimulus (y) were recorded for each of 6 subjects. Times were measured in thousandths of a second. The results are presented in the following table. The following MINITAB output describes the fit of a linear model to these data. Assume that the assumptions of the linear model are satisfied.

The regression equation is Auditory = 192.99901 + 0.335891 Visual Predictor Constant Visual

Coef 192.99901 0.335891

SE Coef 25.608172 0.140635

T 7.536618 2.388391

What is the intercept of the least-squares regression line? A) 0.140635 B) 0.335891 C) 192.99901

P 0.001661 0.0753

D) 7.536618

32)

33) In a study of reaction times, the time to respond to a visual stimulus (x) and the time to

33)

Auditory 241 252 249 244 245 238 243 244

Predict the auditory response time for a particular subject whose visual response time of 180. A) 244.50 B) 238.96 C) 245.68 D) 242.32 34) In a study of reaction times, the time to respond to a visual stimulus (x) and the time to

Auditory 199 239 176 157 152 187 172 194

Compute the least-squares regression line for predicting auditory response time (y) from visual response time (x). A) y = 17.126641 + 0.886746x B) y = 0.886746 + 17.126641x C) y = 0.886746x D) y = 17.126641x

34)

35) The following display from a TI-84 Plus calculator presents the results of a test of the

35)

null hypothesis H 0 : 1 = 0.

y = a+bx 0 and 0 t = 3.187622 p = 0.012849 df = 8 a = 5.72876

How many degrees of freedom did the calculator use? A) 6 B) 10 C) 8

D) 9

36) In a study of reaction times, the time to respond to a visual stimulus (x) and the time to

The regression equation is Auditory = 205.334725 + 0.271259 Visual Predictor Constant Visual

Coef 205.334725 0.271259

SE Coef 36.493752 0.177021

T 5.626572 1.532354

P 0.004908 0.200202

Can you conclude that the response time to visual stimulus is useful in predicting the response time for auditory stimulus? Answer this question using the = 0.05 level of significance. A) No B) Yes

36)

37) The following display from a TI-84 Plus calculator presents the results of a test of the

37)

null hypothesis H 0 : 1 = 0.

y = a+bx 0 and 0 t = 2.987946 p = 0.012343 df = 11 a = 4.040771

What is the value of the test statistic? A) 0.012343 B) 11

C) 4.040771

D) 2.987946

38) Use the given set of points to construct a 95% prediction interval for an individual

response for the given value of x. x 20 20 12 14 20 y 68 68 41 47 68 A) (55.77, 60.09)

11 39

x = 17

B) (57.10, 58.76)

C) (57.29, 58.57)

D) (56.27, 59.59)

39) Use the given set of points to compute b1 .

x 14 15 y 29 29 A) 6.9231

12 30

14 28

9 12 19 25 B) 26.0000

13 30

39)

11 25 C) 1.5962

D) 2.3322

40) Use the given set of points to construct a 95% confidence interval for 1 .

x 7 14 12 12 y 16 35 25 29 A) 1.2550 < 1 < 3.2864

5 13

9 28

38)

8 20

10 30 B) 1.0857 < 1 < 3.4557

C) 1.5159 < 1 < 3.773

D) 1.1422 < 1 < 3.3993

40)

41) Construct the multiple regression sequence y = b0 + b1 x1 + b2 x2 + b3 x3 for the following

data set: y x1 x2 x3 31.3 50 19 4.0 56.9 90 38 8.0 43.1 70 28 6.5 41.5 70 25 5.5 39.0 60 26 6.5 40.9 70 29 5.0 35.9 60 23 5.5 43.5 70 28 5.5 47.9 80 34 6.5 33.8 70 26 4.5 ^

A) y = 2.3760 + 0.3904x1 + 0.2182x2 + 0.3750x3 ^

B) y = 0.3750 + 0.2182x1 + 0.3904x2 + 2.3760x3 ^

C) y = 0.3518 + 0.2129x1 + 0.4167x2 + 2.5798x3 ^

D) y = 2.5798 + 0.4167x1 + 0.2129x2 + 0.3518x3

41)

42) The following MINITAB output presents a multiple regression equation y = b0 + b1 x1 +

b 2 x2 + b 3 x3 + b 4 x4 .

The regression equation is Y = 3.4450 + 1.7492 X1 - 1.3556 X2 - 1.4445 X3 - 0.5639 X4 Predictor Constant X1 X2 X3 X4

Coef 3.4450 1.7492 -1.3556 -1.4445 -0.5639

S = 2.9828

R-Sq = 42.7% R-Sq(adj) = 34.6%

Analysis of Variance Source DF Regression 4 33 Residual Error 37 Total

SE Coef 0.8637 0.8586 0.8189 0.6639 0.7934

T 1.0040 3.1702 -3.2747 1.9428 -1.0036

SS 665.5 891.9 1557.4

MS 166.4 27.0

P 0.340 0.002 0.006 0.088 0.357

F 6.1630

Let 1 be the coefficient X 1 . Test the hypothesis H0: 1 = 0 versus H1 : 1 the = 0.05 level. What do you conclude? A) Reject H 0 B) Do not reject H 0

P 0.003

0 at

42)

43) In a study of reaction times, the time to respond to a visual stimulus (x) and the time to

43)

respond to an auditory stimulus (y) were recorded for each of 8 subjects. Times were measured in thousandths of a second. The results are presented in the following table. Visual 151 189 170 198 192 187 216 159

Auditory 152 187 165 195 183 183 203 157

Construct a 99% confidence interval for the slope of the least-squares regression line. A) (0.6708, 1.0112) B) (24.2307, 24.6322) C) (24.2612, 24.6016) D) (0.6402, 1.0418) 44) In a study of reaction times, the time to respond to a visual stimulus (x) and the time to

44)

Auditory 246 247 245 239 238 241 245 247

Construct a 99% prediction interval for the auditory response time for a particular subject whose visual response time is 183. A) (237.36, 243.12) B) (233.99, 246.49) C) (232.87, 247.61) D) (236.84, 243.64) 45) Use the given set of points to compute the sum of squares for x,

x 7 11 y 20 23 A) 8.6742

10 27

5 11

8 8 28 22 B) 1.5606

14 30

(x - x) .

13 27 C) 66.0000

D) 4.0261

45)

46) The following MINITAB output presents a multiple regression equation y = b0 + b1 x1 +

b 2 x2 + b 3 x3 + b 4 x4 .

The regression equation is Y = 3.4852 + 1.0989 X1 + 1.3596 X2 + 1.9467 X3 - 0.6725 X4 Predictor Constant X1 X2 X3 X4

Coef 3.4852 1.0989 1.3596 1.9467 -0.6725

S = 2.4743

R-Sq = 44.0% R-Sq(adj) = 37.5%

Analysis of Variance Source DF Regression 4 39 Residual Error 43 Total

SE Coef 0.7459 0.8330 0.6263 0.8966 0.7694

T 1.0130 3.4995 -2.9122 1.6438 -0.7715

SS 800.9 1017.9 1818.8

MS 200.2 26.1

P 0.320 0.004 0.009 0.078 0.360

F 7.6705

Predict the value of y when x1 = 3, x2 = 4, x3 = 5, x4 = 7 A) 15.6189

B) 17.2463

C) 13.7611

D) 14.873

P 0.003

46)

47) The following MINITAB output presents a multiple regression equation y = b0 + b1 x1 +

47)

b 2 x2 + b 3 x3 + b 4 x4 .

The regression equation is Y = 4.5918 + 1.3165 X1 + 0.5538 X2 + 1.2215 X3 + 0.6823 X4 Predictor Constant X1 X2 X3 X4

Coef 4.5918 1.3165 0.5538 1.2215 0.6823

S = 2.9694

R-Sq = 34.8% R-Sq(adj) = 22.4%

Analysis of Variance Source DF Regression 4 26 Residual Error 30 Total

SE Coef 0.8467 0.8391 0.7804 0.6493 0.7711

T 0.8953 3.1794 -2.9141 1.8100 -0.7964

SS 554.7 1037.5 1592.2

MS 138.7 39.9

P 0.329 0.003 0.004 0.077 0.342

F 3.4762

P 0.003

What percentage of the variation in y is explained by the model? A) 0.3% B) 3.4762% C) 22.4% D) 34.8% 48) Use the given set of points to compute the standard error of b1 , sb.

x 14 11 y 33 26 A) 78.0000

13 28

15 29

7 12 20 23 B) 0.3201

6 17

48)

14 34 C) 2.8273

49) Under the assumptions of the linear model, the values of y x follow a A) straight line

B) normal curve

C) exponential curve

D) random pattern

D) 1.6154

49)

50) The following MINITAB output presents a multiple regression equation y = b0 + b1 x1 +

50)

b 2 x2 + b 3 x3 + b 4 x4 .

The regression equation is Y = 2.0032 + 1.6066 X1 + 0.8239 X2 - 1.0189 X3 + 0.6460 X4 Predictor Constant X1 X2 X3 X4

Coef 2.0032 1.6066 0.8239 -1.0189 0.6460

SE Coef 0.8059 0.8339 0.7293 0.8628 0.7469

S = 2.6301

R-Sq = 53.4% R-Sq(adj) = 46.2%

Analysis of Variance Source DF Regression 4 31 Residual Error 35 Total

T 0.8596 3.5187 -2.9230 1.9056 -0.8587

SS 775.8 677.1 1452.9

MS 194.0 21.8

P 0.311 0.004 0.004 0.081 0.351

F 8.8991

P 0.003

Is the model useful for prediction? Use the = 0.05 level. A) No B) Yes 51) Use the given set of points to compute the sum of squares for x,

x y

17 58

17 57

19 63

A) 2.943343

16 54

10 37

12 42

(x - x) .

x = 12

B) 58.833333

C) 15.166667

D) 0.534901

52) Use the given set of points to compute the predicted value y for the given value of x.

x y

12 32

A) 122.9413

18 45

12 33

18 43

20 49

15 39

51)

x = 14

B) 120.9501

C) 36.5161

D) 27.8768

52)

53) The summary statistics for a certain set of points are: n = 17, se = 2.468,

53)

(x - x) = 19.966, and b1 = 1.764. Assume the conditions of the linear model hold. A 99% confidence interval for 1 will be constructed. Construct the 99% confidence interval. A) 0.1506 < 1 < 3.3774

B) 0.1363 < 1 < 3.3917

C) 0.3268 < 1 < 3.2012

D) 0.3368 < 1 < 3.3774

54) The summary statistics for a certain set of points are: n = 28, se = 2.700,

54)

(x - x) = 19.308, and b1 = 1.815. Assume the conditions of the linear model hold. A 95% confidence interval for 1 will be constructed. How many degrees of freedom are there for the critical value? A) 26 B) 28 C) 29

D) 27

55) In a study of reaction times, the time to respond to a visual stimulus (x) and the time to

The regression equation is Auditory = 171.840525 + 0.45095 Visual Predictor Constant Visual

Coef 171.840525 0.45095

SE Coef 11.943218 0.058314

T 14.388126 7.733073

What is the slope of the least-squares regression line? A) 0.058314 B) 0.45095 C) 171.840525

P 0.000137 0.001507

D) 14.388126

55)

56) In a study of reaction times, the time to respond to a visual stimulus (x) and the time to

56)

Auditory 245 246 245 248 238 247 248 244

Test H 0 : 1 = 0 versus H 1 : 1 0. Use the A) Reject H 0 .

= 0.01 level of significance. B) Do not reject H 0 .

57) The following MINITAB output presents a 99% confidence interval for the mean ozone

level on days when the relative humidity is 35%, and a 99% prediction interval for the ozone level on a particular day when the relative humidity is 35%. The units of ozone are parts per billion. Predicted Values for New Observations New Obs 1

Fit 36.80

SE Fit 1.6

99.0% CI (32.68, 40.92)

99.0% PI (21.39, 52.21)

Values of Predictors for New Observations New OBS 1

Humidity 35.0%

Predict the ozone level for a day when the relative humidity is 35%. A) 32.68 B) 1.6 C) 35.0

D) 36.80

57)

58) The following display from a TI-84 Plus calculator presents the results of a test of the

58)

null hypothesis H 0 : 1 = 0.

y = a+bx 0 and 0 t = 2.1165 p = 0.060378 df = 10 a = 9.326661

Can you conclude that the explanatory variable is useful in predicting the outcome variable? Answer this question using the = 0.05 level of significance. A) Yes B) No TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 59) Under the assumptions of the linear model, the residual plot will exhibit a linear pattern.

59)

60) Under the assumptions of the linear model, the vertical spread in a residual plot will be

60)

about the same across the plot.

Answer Key Testname: C13

1) B 2) B 3) B 4) D 5) C 6) A 7) D 8) i). y = 223.727501 + 0.098633x

ii). (0.0214, 0.1759) iii). Reject H 0. 9) (4.106, 17.090) 10) (1.861, 14.929) 11) a). b0 = 8.410463; b1 = 2.006036

b). 40.507039 c). 0.61176 d). 82.8333333 e). 2.776 f). (39.78, 41.23) g). (38.66, 42.35) 12) i). 10 ii). 2.228 iii). 1.867565 iv). -0.4206 < 1 < 3.3146 13) i). 243.91

ii). (242.64, 245.18) iii). 243.91 iv). (240.81, 247.01) 14) a). 1.6429 b). 3.2385 c). 101.5000 d). 0.3215 e). 3.707 f). 1.1916 g). 0.4512 < 1 < 2.8345 h). Reject H 0 . 15) A 16) C 17) D 18) B 19) B 20) B 21) B 28

Answer Key Testname: C13

22) C 23) A 24) A 25) B 26) D 27) A 28) B 29) C 30) A 31) D 32) C 33) D 34) A 35) C 36) A 37) D 38) A 39) C 40) D 41) C 42) A 43) D 44) C 45) C 46) B 47) D 48) B 49) A 50) B 51) B 52) C 53) B 54) A 55) B 56) B 57) D 58) B 59) FALSE 60) TRUE

Exam Name___________________________________

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. 1) In a water-bottling facility, several machines fill plastic bottles with 16 ounces of

drinking water. The following TI-84 Plus display presents the results of a one-way ANOVA to determine whether the mean fill volumes differ among the filling machines.

F = 7.830986 p = 0.00369 Factor df = 3 SS = 0.695 MS = 0.231667

MS =0.231667 Error df = 12 SS = 0.355 MS = 0.029583 Sxp = 0.171998

i). State the null hypothesis. ii). How many filling machines were involved in the study? iii). Assume the design was balanced. How many water bottles were measured for each filling machine? iv). What are the values of SSTr, SSE, MSTr, and MSE? v). What is the value of the test statistic? vi). What is the P-value? vii). Can you conclude that the mean fill volume differs among the filling machines? Use the = 0.01 level of significance. 2) The following table shows the weekly total sales (in dollars) at a small roadside

vegetable stand for the months June through September. Month June July August September

Weekly Sales 770 1092 1154 924

1065 1000 1259 943

1041 1033 1008 868

930 1069 917 931

i). Construct an ANOVA table. ii). Can you conclude that the weekly sales varies with the month? Use the = 0.05 level of significance.

3) One of the factors that determines the degree of risk a pesticide poses to human

health is the rate at which it is absorbed into the skin after contact. An important question is whether the amount in the skin continues to increase with the length of the contact, or whether it increases for only a short time before leveling off. To investigate this, measured amounts of a certain pesticide were applied to 20 samples of rat skin. Four skins were analyzed at each of the time intervals 1, 2, 4, 10, and 24 hours. The amounts of the chemical (in micrograms) that were in the skin are given in the following table: Duration 1 2 4 10 24

1.2 1.1 1.4 1.6 1.7

1.5 1.4 1.4 1.7 1.8

1.3 1.2 1.2 1.5 1.8

1.7 1.6 1.7 2.0 1.9

Construct an ANOVA table for this data. 4) The following table presents measurements of the tensile strength (in kilopascals)

of asphalt-rubber concrete beams for three levels of binder content and three levels of rubber content. Low Rubber

Medium Rubber

Content Content

Content

High

Rubber

105.8 130.9 117.4 Low Binder Content Medium Binder Content 117.0 125.0 129.9 High Binder Content 102.9 99.1 101.5

108.5 112.1 108.6 118.0 106.0 136.6 115.2 107.1 127.4

134.3 124.3 123.1 139.8 120.6 123.3

i). Can you reject the hypothesis of no interactions? ii). Can the mean effect of the binder content be interpreted? If so, interpret the main effect. Use the = 0.01 level of significance. iii). Can the mean effect of the rubber content be interpreted? If so, interpret the main effect. Use the = 0.01 level of significance.

134.6 106.5 115.1

5) Artificial hip joints consist of a ball and socket. As the joint wears, the ball (head)

becomes rough. Investigators performed wear tests on metal, artificial hip joints. Joints with several different diameters were tested. The following table presents measurements of head roughness (in nanometers). Diameter 16 24 30

Head Roughness 21.9 30.6 25.2

27.5 33.1 27.6

27.1 33.7 24.3

22.6

i). Construct an ANOVA table. ii). Can you conclude that the mean roughness varies with diameter? Use the = 0.05 level of significance. 6) In one-way ANOVA, the null hypothesis states that all the population means are

. 7) An experiment is conducted to study the effects of curing times and curing

temperatures on the bonding strength of an epoxy adhesive. In the experiment, two steel rods are adhered together end-to-end, and the bonding strength is defined as the force, in pounds, required to pull the bond apart. For each combination of curing time and curing temperature, three tests are performed. The results of the experiment are shown below.

Low cure temp High cure temp

1-hr cure time

2-hr cure time

3-hr cure time

8.1 7.9 7.9 7.9 8.0 8.1

7.9 8.0 8.0 8.1 8.2 8.0

8.0 8.0 8.1 8.2 8.1 8.3

i). Can you reject the hypothesis of no interactions? ii). Can the main effect of curing temperature (low or high) on bonding strength be interpreted? If so, interpret the main effect using the = 0.05 level of significance. iii). Can the main effect of curing time on bonding strength be interpreted? If so, interpret the main effect using the = 0.05 level of significance.

8) Samples were drawn from three populations. The sample sizes were n1 = 9,

n2 = 6, and n3 = 7. The sample means were x1 = 2.52, x2 = 2.30, and x3 = 1.46. The sample standard deviations were s1 = 0.31, s2 = 0.46, and s3 = 0.26. The grand mean is x = 2.122727. i). Compute the sums of squares SSTr and SSE. ii). How many degrees of freedom are there for SSTr and SSE? iii). Compute the sums of squares MSTr and MSE. iv). Compute the value of the test statistic F. v). Can you conclude that two or more of the population means are different? Use the = 0.05 level of significance. 9) In a one-way ANOVA, the following data were collected: SSTr = 0.42,

SSE = 2.37, N = 24, I = 3. i). How many samples are there? ii). How many degrees of freedom are there for SSTr and SSE? iii). Compute the mean squares MSTr and MSE. iv). Compute the value of the test statistic F.

10) An agricultural scientist performs a 2-way ANOVA to determine the effects of

10)

three different soil mixtures on the sprouting time (in days) of three varieties of hybrid cucumber seeds. The following MINITAB output presents the results. Analysis of Variance for Sprouting Source Soil Mixture Hybrid Variety Interaction Error Total P 0.031306 0.065912 0.471214

DF 2 2 4 18 26

SS 12.518519 9.407407 5.481481 26.666667 54.074074

MS 6.259259 4.703704 1.37037 1.481481

F 4.225 3.175 0.925

i). Can you reject the hypothesis of no interactions? ii). Can the mean effect of the soil mixture be interpreted? If so, interpret the main effect. Use the = 0.05 level of significance. iii). Can the mean effect of the hybrid variety be interpreted? If so, interpret the main effect. Use the = 0.05 level of significance. MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 11) Samples were drawn from three populations. The sample sizes were n1 = 6, n2 = 9, and

n3 = 6. The sample means were x1 = 1.20, x2 = 1.27, and x3 = 1.65. The sample standard deviations were s1 = 0.37, s2 = 0.28, and s3 = 0.46. The grand mean is x = 1.358571. Compute the mean squares MSE. A) 2.3697 B) 0.3655

C) 0.7311

D) 0.1317

11)

12) The following table shows the weekly total sales (in dollars) at a small roadside

12)

vegetable stand for the months June through September. Month June July August September

Weekly Sales 1184 1086 1205 1055

998 955 1038 1230

1020 990 1140 1312

894 912 1206 1020

Can you conclude that the weekly sales varies with the month? Use the significance. A) No B) Yes

= 0.01 level of

13) The following table shows the weekly total sales (in dollars) at a small roadside

vegetable stand for the months June through September. Month June July August September

Weekly Sales 926 922 1162 824

1037 1140 1034 829

916 1207 1110 884

1150 928 1322 828

Perform a Tukey-Kramer test to determine which pairs of means, if any, differ. Use the = 0.01 level of significance. A) July

Aug

B) June

Aug, Aug

C) Aug

Sept

D) There is not enough evidence to conclude that any of the means differ.

13)

14) An agricultural scientist performs a 2-way ANOVA to determine the effects of three

14)

different soil mixtures on the sprouting time (in days) of three varieties of hybrid cucumber seeds. The following MINITAB output presents the results. Analysis of Variance for Sprouting Source Soil Mixture Hybrid Variety Interaction Error Total

DF 2 2 4 18 26

SS 6.222222 13.555556 26.888889 26 72.666667

MS 3.111111 6.777778 6.722222 1.444444

F P 2.153846 0.144998 4.692308 0.022903 4.653846 0.009349

Can you reject the hypothesis of no interactions? A) Yes B) No 15) Samples were drawn from three populations. The sample sizes were n1 = 7, n2 = 7, and

15)

n3 = 5. The sample means were x1 = 1.85, x2 = 1.70, and x3 = 1.69. The sample standard deviations were s1 = 0.41, s2 = 0.44, and s3 = 0.25. The grand mean is x = 1.752632. Compute the sum of squares SSE. A) 2.4202 B) 0.1054

C) 0.3483

D) 0.0527

16) When the effect of one factor depends on the level of another factor, an

present. A) interaction C) unbalanced design

B) assumption D) error

17) An experiment is conducted to study the effects of curing times and curing temperatures

on the bonding strength of an epoxy adhesive. In the experiment, two steel rods are adhered together end-to-end, and the bonding strength is defined as the force, in pounds, required to pull the bond apart. For each combination of curing time and curing temperature, three tests are performed. The results of the experiment are shown below.

Low cure temp High cure temp

16)

1-hr cure time

2-hr cure time

3-hr cure time

8.1 8.1 8.0 8.0 8.1 8.1

7.9 8.0 7.9 8.1 8.1 8.2

8.0 7.9 8.2 8.3 8.1 8.2

Can you reject the hypothesis of no interactions? A) Yes B) No

17)

18) Samples were drawn from three populations. The sample sizes were n1 = 7, n2 = 9, and

18)

n3 = 7. The sample means were x1 = 2.20, x2 = 2.41, and x3 = 2.07. The sample standard deviations were s1 = 0.44, s2 = 0.43, and s3 = 0.30. The grand mean is x = 2.242609. Can you conclude that two or more of the population means are different? Use the = 0.01 level of significance. A) Yes B) No 19) Interpret the interaction plot by explaining whether there appear to be large interactions

19)

between factors.

A) Interactions are not large

B) Interactions are large

20) The following table presents measurements of the tensile strength (in kilopascals) of

asphalt-rubber concrete beams for three levels of binder content and three levels of rubber content. Low Rubber

Medium Rubber

High Rubber

Content

127.4 121.4 100.3 107.6 116.5 118.6 111.8 107.6 118.9

123.8 133.2 126.0 123.7 108.1 120.1 136.1 119.2 119.4

132.6 117.7 145.4 Low Binder Content Medium Binder Content 116.2 107.4 94.8 High Binder Content 103.8 117.4 120.4

Can the mean effect of the binder content be interpreted? If so, interpret the main effect. Use the = 0.05 level of significance. A) Yes. Reject H 0 . B) No. C) Yes. Do not reject H 0 .

20)

21) In a one-way ANOVA, the following data were collected: SSTr = 0.35, SSE = 2.33,

21)

N = 28, I = 3. Compute the mean squares MSE. A) 1.8777 B) 0.1750

C) 0.0140

D) 0.0932

22) An experiment is conducted to study the effects of curing times and curing temperatures

22)

Low cure temp High cure temp

1-hr cure time

2-hr cure time

3-hr cure time

8.0 8.0 8.1 7.9 8.0 8.2

8.1 8.0 8.2 8.2 8.1 8.2

8.2 8.0 8.0 8.2 8.1 8.2

Can the main effect of curing temperature (low or high) on bonding strength be interpreted? If so, interpret the main effect using the = 0.01 level of significance. A) Yes. Do not reject H 0 . B) Yes. Reject H 0 . C) No. 23) An agricultural scientist performs a 2-way ANOVA to determine the effects of three

DF 2 2 4 18 26

SS 12.962963 3.185185 8.814815 28 52.962963

MS 6.481481 1.592593 2.203704 1.555556

F P 4.166667 0.032576 1.02381 0.379217 1.416667 0.268663

Can the mean effect of the soil mixture be interpreted? If so, interpret the main effect. Use the = 0.01 level of significance. A) Yes. Do not reject H 0 . B) Yes. Reject H 0 . C) No.

23)

24) In a one-way ANOVA, the following data were collected: SSTr = 0.43, SSE = 1.53,

24)

N = 35, I = 6. Compute the value of the test statistic F. A) 0.0148 B) 0.0528

C) 1.6301

D) 0.0860

25) In two-way ANOVA, the factors can have two kinds of effects on the response:

and

25)

A) main; interaction

B) main; unbalanced

C) interaction; error

D) main; error

26) In a one-way ANOVA, the following data were collected: SSTr = 0.23, SSE = 1.75,

26)

N = 22, I = 5. How many samples are there? A) 4 B) 5

C) 22

D) 17

27) One of the factors that determines the degree of risk a pesticide poses to human health is

27)

the rate at which it is absorbed into the skin after contact. An important question is whether the amount in the skin continues to increase with the length of the contact, or whether it increases for only a short time before leveling off. To investigate this, measured amounts of a certain pesticide were applied to 20 samples of rat skin. Four skins were analyzed at each of the time intervals 1, 2, 4, 10, and 24 hours. The amounts of the chemical (in micrograms) that were in the skin are given in the following table: Duration 1 2 4 10 24

1.2 1.1 1.4 1.6 1.7

1.5 1.4 1.4 1.7 1.8

1.3 1.2 1.2 1.5 1.8

1.7 1.6 1.7 2.0 1.9

Can you conclude the amount in the skin varies with time? Use the significance. A) Yes B) No

= 0.05 level of

28) In a one-way ANOVA, the following data were collected: SSTr = 0.39, SSE = 2.14,

N = 30, I = 3. Compute the mean squares MSTr. A) 0.0144 B) 0.1950

C) 2.4603

D) 0.0793

28)

29) In a one-way ANOVA, the following data were collected: SSTr = 0.4, SSE = 1.53,

29)

N = 36, I = 4. How many degrees of freedom are there for SSE? A) 3 B) 36 C) 4

D) 32

30) Samples were drawn from three populations. The sample sizes were n1 = 5, n2 = 7, and

30)

n3 = 6. The sample means were x1 = 1.34, x2 = 1.63, and x3 = 1.68. The sample standard deviations were s1 = 0.46, s2 = 0.50, and s3 = 0.34. The grand mean is x = 1.566111. How many degrees of freedom are there for SSE. A) 3 B) 14 C) 15

D) 2

31) Interpret the interaction plot by explaining whether there appear to be large interactions

between factors.

A) Interactions are large

B) Interactions are not large

31)

32) In a water-bottling facility, several machines fill plastic bottles with 16 ounces of

32)

drinking water. The following TI-84 Plus display presents the results of a one-way ANOVA to determine whether the mean fill volumes differ among the filling machines.

F = 9.241379 p = 0.001918 Factor df = 3 SS = 0.335 MS = 0.111667

MS = 0.111667 Error df = 12 SS = 0.145 MS = 0.012083 Sxp = 0.109924

Can you conclude that the mean fill volume differs among the filling machines? Use the = 0.01 level of significance. A) No B) Yes 33) An experiment is conducted to study the effects of curing times and curing temperatures

Low cure temp High cure temp

1-hr cure time

2-hr cure time

3-hr cure time

8.0 8.0 7.9 8.1 8.1 7.9

8.0 8.1 8.0 8.0 8.1 8.1

8.1 8.1 8.2 8.2 8.2 8.1

Can the main effect of curing time on bonding strength be interpreted? If so, interpret the main effect. using the = 0.05 level of significance. A) Yes. Reject H 0 . B) Yes. Do not reject H 0 . C) No.

33)

34) The following table presents measurements of the tensile strength (in kilopascals) of

34)

asphalt-rubber concrete beams for three levels of binder content and three levels of rubber content. Low Rubber

Medium Rubber

High Rubber

Content

112.8 124.3 114.7 116.7 97.1 103.7 111.8 92.3 104.3

116.4 110.0 118.2 119.9 112.5 113.5 129.5 113.7 123.6

130.5 120.5 117.8 Low Binder Content Medium Binder Content 110.1 128.9 107.9 High Binder Content 115.0 94.8 100.5

Can you reject the hypothesis of no interactions? A) No B) Yes 35) In a water-bottling facility, several machines fill plastic bottles with 16 ounces of

drinking water. The following TI-84 Plus display presents the results of a one-way ANOVA to determine whether the mean fill volumes differ among the filling machines.

F = 4.239264 p = 0.029302 Factor df = 3 SS = 0.431875 MS = 0.143958

MS = 0.143958 Error df = 12 SS = 0.4075 MS = 0.033958 Sxp = 0.184278

What is the value of SSTr? A) 0.431875 B) 0.4075

C) 0.033958

D) 0.143958

35)

36) One of the factors that determines the degree of risk a pesticide poses to human health is

36)

1.3 1.3 1.3 1.5 1.8

1.5 1.7 2.0 2.2 2.4

1.2 1.4 1.4 1.4 1.7

1.4 1.7 1.8 1.9 2.2

Perform the Tukey-Kramer test to determine which pairs of means, if any, differ. Use the = 0.05 level of significance. A) There is not enough evidence to conclude that any of the means differ. B)

37) In a water-bottling facility, several machines fill plastic bottles with 16 ounces of

drinking water. The following TI-84 Plus display presents the results of a one-way ANOVA to determine whether the mean fill volumes differ among the filling machines.

F = 2.571429 p = 0.102859 Factor df = 3 SS = 0.36 MS = 0.12

MS = 0.12 Error df = 12 SS = 0.56 MS = 0.046667 Sxp = 0.216025

What is the value of the test statistic? A) 0.36 B) 0.046667

C) 0.102859

D) 2.571429

37)

38) Samples were drawn from three populations. The sample sizes were n1 = 9, n2 = 9, and

38)

n3 = 9. The sample means were x1 = 1.31, x2 = 1.59, and x3 = 1.41. The sample standard deviations were s1 = 0.38, s2 = 0.32, and s3 = 0.48. The grand mean is x = 1.436667. How many degrees of freedom are there for SSTr. A) 24 B) 23 C) 2

D) 3

39) Samples were drawn from three populations. The sample sizes were n1 = 5, n2 = 5, and

39)

n3 = 7. The sample means were x1 = 1.41, x2 = 1.95, and x3 = 1.39. The sample standard deviations were s1 = 0.33, s2 = 0.45, and s3 = 0.41. The grand mean is x = 1.560588. Compute the mean squares MSTr. A) 0.5376 B) 2.2542

C) 1.0753

D) 3.3391

40) An agricultural scientist performs a 2-way ANOVA to determine the effects of three

DF 2 2 4 18 26

SS 16.074074 5.851852 11.259259 46.666667 79.851852

MS 8.037037 2.925926 2.814815 2.592593

F P 3.1 0.069681 1.128571 0.345342 1.085714 0.393039

Can the mean effect of the hybrid variety be interpreted? If so, interpret the main effect. Use the = 0.05 level of significance. A) Yes. Do not reject H 0 . B) Yes. Reject H 0 . C) No.

40)

41) Artificial hip joints consist of a ball and socket. As the joint wears, the ball (head)

41)

becomes rough. Investigators performed wear tests on metal artificial; hip joints. Joints with several different diameters were tested. The following table presents measurements of head roughness (in nanometers). Diameter

Head Roughness 25.7 29.7 26.8

16 24 30

24.9 32.2 26.2

16.8 34.9 20.7

23.4

Perform the Tukey-Kramer test to determine which pairs of means, if any, differ. Use the = 0.05 level of significance. A) 16

24, 24

B) 16

C) 16

24, 16

D) There is not enough evidence to conclude that any of the means differ. 42) In a water-bottling facility, several machines fill plastic bottles with 16 ounces of

drinking water. The following TI-84 Plus display presents the results of a one-way ANOVA to determine whether the mean fill volumes differ among the filling machines.

F = 2.15847 p = 0.14604 Factor df = 3 SS = 0.246875 MS = 0.082292

MS = 0.082292 Error df = 12 SS = 0.4575 MS = 0.038125 Sxp = 0.195256

What is the value of MSE? A) 0.082292 B) 0.246875

C) 0.4575

D) 0.038125

42)

43) In a water-bottling facility, several machines fill plastic bottles with 16 ounces of

43)

drinking water. The following TI-84 Plus display presents the results of a one-way ANOVA to determine whether the mean fill volumes differ among the filling machines.

F = 2.064516 p = 0.158544 Factor df = 3 SS = 0.16 MS = 0.053333

MS = 0.053333 Error df = 12 SS = 0.31 MS = 0.025833 Sxp = 0.160728

What is the value of SSE? A) 0.16 B) 0.053333

C) 0.025833

D) 0.31

44) The following table presents measurements of the tensile strength (in kilopascals) of

44)

asphalt-rubber concrete beams for three levels of binder content and three levels of rubber content. Low Rubber

Medium Rubber

High Rubber

Content

110.9 119.0 114.6 114.8 110.7 121.1 127.2 103.8 106.5

117.5 126.5 120.9 132.2 121.9 132.7 133.0 113.8 120.5

133.0 118.9 112.4 Low Binder Content Medium Binder Content 118.6 117.0 102.3 High Binder Content 122.6 98.9 104.7

Can the mean effect of the rubber content be interpreted? If so, interpret the main effect. Use the = 0.05 level of significance. A) No. B) Yes. Reject H 0 . C) Yes. Do not reject H 0 . 45) Samples were drawn from three populations. The sample sizes were n1 = 7, n2 = 7, and

n3 = 9. The sample means were x1 = 1.72, x2 = 1.52, and x3 = 1.20. The sample standard deviations were s1 = 0.36, s2 = 0.49, and s3 = 0.30. The grand mean is x = 1.455652. Compute the value of the test statistic F. A) 2.938 B) 1.106

C) 0.553

D) 3.765

45)

46) In a water-bottling facility, several machines fill plastic bottles with 16 ounces of

46)

drinking water. The following TI-84 Plus display presents the results of a one-way ANOVA to determine whether the mean fill volumes differ among the filling machines.

F = 5.457627 p = 0.013391 Factor df = 3 SS = 0.4025 MS = 0.134167

MS = 0.134167 Error df = 12 SS = 0.295 MS = 0.024583 Sxp = 0.156791

What is the value of MSTr? A) 0.024583 B) 0.134167

C) 0.4025

D) 0.295

47) Samples were drawn from three populations. The sample sizes were n1 = 9, n2 = 7, and

47)

n3 = 7. The sample means were x1 = 1.83, x2 = 1.29, and x3 = 1.82. The sample standard deviations were s1 = 0.25, s2 = 0.50, and s3 = 0.40. The grand mean is x = 1.662609. Compute the sum of squares SSTr. A) 1.3974 B) 0.6987

C) 2.9600

D) 4.7211

48) Interpret the interaction plot by explaining whether there appear to be large interactions

48)

between factors.

A) Interactions are large

B) Interactions are not large

49) In a one-way ANOVA, the following data were collected: SSTr = 0.28, SSE = 2.37,

N = 37, I = 5. How many degrees of freedom are there for SSTr? A) 4 B) 32 C) 5 18

D) 37

49)

50) In a water-bottling facility, several machines fill plastic bottles with 16 ounces of

50)

drinking water. The following TI-84 Plus display presents the results of a one-way ANOVA to determine whether the mean fill volumes differ among the filling machines.

F = 2.099237 p = 0.153787 Factor df = 3 SS = 0.171875 MS = 0.57292

What is the P-value? A) 2.099237

MS = 0.57292 Error df = 12 SS = 0.3275 MS = 0.027292 Sxp = 0.165202

B) 0.153787

C) 0.171875

D) 0.027292

51) Artificial hip joints consist of a ball and socket. As the joint wears, the ball (head)

51)

Head Roughness 26.3 36.2 26.3

25.6 36.1 26.3

29.3 30.6 19.3

21.9

Can you conclude that the mean roughness varies with diameter? Use the of significance. A) Yes B) No

= 0.01 level

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 52) In two-way ANOVA, we should not interpret the main effects when there are no

52)

interactions. 53) In two-way ANOVA, the results can be difficult to interpret if the design is unbalanced.

53)

54) In one-way ANOVA, we have samples from several populations.

54)

Answer Key Testname: C14

1) i). H 0 : The mean fill volume is the same for all the machines.

ii). 4 machines iii). 4 bottles iv). SSTr = 0.695; SSE = 0.355; MSTr = 0.231667; MSE = 0.029583 v). 7.830986 vi). 0.00369 vii). Yes 2) i). Source DF SS MS F P

Month Error Total

3 12 15

ii).No Source DF

Factor Error 3) Total

4 15 19

75267 131712 206979

25089 10976

2.285805

0.130839

0.663 0.583 1.246

0.166 0.037

4.268

113.229833 37.054167 150.284

56.614917 5.293452

0.017

4) i). No.

ii). Yes. Do not reject H 0 . iii). Yes. Do not reject H 0 . 5) i).

Source DF Month Error Total

2 7 9

10.695273 0.007443

ii).Yes 6) equal 7) i). No ii). Reject H 0 .

iii). Do not reject H 0 . 8) i). SSTr = 4.6834; SSE = 2.2324

ii). degrees of freedom for SSTr = 2; degrees of freedom for SSE = 19 iii). MSTr = 2.3417; MSE = 0.1175 iv). 19.930 v). Yes

Answer Key Testname: C14

9) i). 3

ii). degrees of freedom for SSTr = 2 degrees of freedom for SSE = 21 iii). MSTr = 0.2100; MSE = 0.1129 iv). 1.8601 10) i). No. ii). Yes. Reject H 0.

iii). Yes. Do not reject H 0 . 11) D 12) A 13) C 14) A 15) A 16) A 17) B 18) B 19) A 20) A 21) D 22) A 23) A 24) C 25) A 26) B 27) A 28) B 29) D 30) C 31) B 32) B 33) A 34) B 35) A 36) C 37) D 38) C 39) A 40) A 41) B 42) D 43) D 44) B 45) D 46) B 47) A 48) A 49) A 50) B 51) B 21

Answer Key Testname: C14

52) FALSE 53) TRUE 54) TRUE

Exam Name___________________________________

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) If two or more values are the same when assigning ranks, we assign them the

of the preliminary ranks. A) medians B) rank-sums

C) average

D) modes

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. 2) Monthly rents were recorded for a sample of 36 apartments in a certain city. The

results were as follows. 880 1310 1300 1340 880 930

1190 990 910 1230 1230 860

960 1070 1340 1020 900 940

1170 930 930 1080 860 1160

1040 1010 960 1050 1060 900

1050 1020 850 950 1320 940

Can you conclude that the median rent is less than $1100 per month? Use the 0.05 level of significance.

a. State appropriate null and alternate hypotheses. b. Compute the test statistic. c. Find the critical value. d. State a conclusion. 3) The owners of a coffee stand hypothesize that the median number of sales during

the hour from 10:00 AM to 11:00 AM is 25. They tabulated the following random sample of the number of sales during the time period. 22 28 26 24 26 26 27 29 23 27 29 28 29 24 23 Use the = 0.05 level of significance and provide the following to provide the following information: a. State appropriate null and alternate hypotheses. b. Compute the test statistic. c. Find the critical value. d. State a conclusion.

4) Heights, in feet, of a sample of 24 mature oak trees in a forest were measured.

The results were as follows. 58 58 57 48 61 59 59 55 65 65 41 63 41 62 55 62 60 50 63 60 56 50 55 57 Can you conclude that the median height of oak trees in this forest is greater than 55 feet? Use the = 0.05 level of significance. a. State appropriate null and alternate hypotheses. b. Compute the test statistic. c. Find the critical value. d. State a conclusion. 5) The sign test is performed to test H 0 : m = 400 versus H 1 : m < 400. There are 13

plus signs, 24 minus signs, and 2 zeros. a. What is the test statistic? b. Is H 0 rejected at the = 0.05 level? c. Is H 0 rejected at the

= 0.01 level?

6) A sample of 10 students took a class online and 12 students took an equivalent

class in a traditional classroom. Both classes were given the same final exam three weeks after the end of the courses. The scores were as follows. Online Traditional

67 84 63 94 65 78 63 72 82 76 74 70 87 90 95 73 96 68 90 64 92 80

Can you conclude that the median score for the online class is less than for the traditional class? Use the = 0.05 level of significance. a) State the null and alternate hypotheses. b) Compute the value of the test statistic. c) Compute the P-value. d) State a conclusion

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 7) The length of time that customers spent eating dinner was compared with and without

music playing. The times, in minutes, were as follows. Without Music 55 67 59 55 43 76 45 60 93 61 63 51 With Music 79 87 63 79 48 89 97 80 107 43 100 73 104 84 70 a) Compute the P-value. b) Can you conclude that the median times eating dinner differ with and without music? Use the = 0.01 level of significance. A) a) 0.0086

b) No, you cannot conclude that the median times are different. B) a) 0.0124 b) No, you cannot conclude that the median times are different. C) a) 0.0124 b) Yes, you can conclude that the median times are different. D) a) 0.0086 b) Yes, you can conclude that the median times are different. 8) Fill in the blank with the appropriate word or phrase.

The null hypothesis for the rank-sum test is that the two population A) medians

B) rank-sums

C) means

are equal. D) modes

9) Fill in the blank with the appropriate word or phrase.

When performing the Rank-sum test we reject the null hypothesis when ? A) the P-value

B) the test statistic

C) the test statistic <

D) the P-value >

10) The sign test is performed to test H 0 : m = 32 versus H 1 : m < 32. There are 14 positive

signs and 19 negative signs in a test involving 33 samples. What is the value of the test statistic? A) 0.87 B) -0.87 C) -0.70 D) 1.04

10)

11) A wild life biologist believes that the median length of the fish in a lake is 36 cm. A

11)

random sample of 14 fish yields the following lengths: 21 21 23 25 25 27 28 30 31 33 36 38 42 44 Test the biologist's hypothesis at = 0.05. A) Do not reject the claim because the test value 3 is equal to the critical value 3. B) Reject the claim because the test value 4 is more than the critical value 3. C) Reject the claim because the test value 4 is more than the critical value 2. D) Do not reject the claim because the test value 3 is more than the critical value 2. 12) A consumer advice web site tested a fuel additive. The distance that 12 cars could travel

12)

on five gallons of gasoline was recorded without and then with the additive. The results were as follows. Car 1 2 3 4 5 6 7 8 9 10 11 12 No Additive 105 139 185 108 187 134 170 161 145 115 190 121 With additive 115 157 191 108 197 139 183 168 159 115 193 127 a) Compute the test statistic b) Can you conclude that the median distance traveled with the additive difference from the median distance traveled with the additive? Use the = 0.05 level of significance. A) a) S = 9

b) We cannot conclude that the median distances are different. B) a) S = 12 b) We can conclude that the median distances are different. C) a) S = 9 b) We can conclude that the median distances are different. D) a) S = 12 b) We cannot conclude that the median distances are different. 13) The sign test is performed to test H 0 : m = 45 versus H 1 : m

45. There are 13 positive

signs and 5 negative signs. What is the value of the test statistic? A) 13 B) -8 C) 5 14) Find the critical value at the

D) 8

= 0.05 level for the following sample, for testing H 0 : m =

55 versus H 1 : m > 55. 40 70 63 55 44 69 67 54 55 70 66 53 67 64 A) 3 B) 1 C) 4

13)

D) 2

14)

15) Given n1 = 20, n2 = 26, S = 516, and H 1 : m 1 > m 2 , compute z. A) 1.77

B) 21.85

16) Find the critical value at the

60 versus H 1 : m

C) 1.02

15) D) 0.59

= 0.05 level for the following sample, for testing H 0 : m =

60.

77 64 79 79 42 80 74 54 60 63 50 56 A) 2 B) 1 C) 3

D) 4

17) Given n1 = 14, n2 = 26, S = 283, and H 1 : 1 < 2 , compute s. A) 287

16)

B) 316

C) -0.11

17) D) 35.27

18) For the following data, compute the test statistic and the critical value, and determine

whether to reject H 0 at the

18)

= 0.10 level.

Sample A 40 51 51 45 42 44 43 53 Sample B 25 40 34 51 29 29 38 62 A) S = 5, Critical value is 6, Do not reject H 0 B) S = 6, Critical value is 4, Reject H 0 C) S = 6, Critical value is 4, Do not reject H 0 D) S = 5, Critical value is 6, Reject H 0 19) Given n1 = 19, n2 = 30, S = 401, and H 1 : m 1 A) 0.9357

19)

m 2 , find the P-value.

B) 0.0322

C) 0.1286

D) 0.0643

20) If the test value for a signed-rank test is 18, the sample size is 13, and the test is to be

carried out at the = 0.05 level of significance, should the null hypothesis be rejected? Use the table of critical values for the signed-rank test below. n = 0.10 = 0.05 = 0.02 = 0.01 9 8 6 3 2 10 11 8 5 3 11 14 11 7 5 12 17 14 10 7 13 21 17 13 10 A) Do not reject H 0 because the test value 18 is less than the critical value 20. B) Do not reject H 0 because the test value 18 is greater than the critical value 17. C) Reject H 0 because the test value 18 is less than the critical value 20. D) Reject H 0 because the test value 18 is greater than the critical value 17.

20)

21) Ten subjects were weighed before and after a new diet. The results were as follows.

21)

Subject 1 2 3 4 5 6 7 8 9 10 Before 151 183 222 176 193 202 150 200 178 190 After 135 164 206 188 199 202 139 195 178 198 a) Compute the test statistic b) Can you conclude that the median weight differs before and after the diet? Use the = 0.05 level of significance. A) a) S = 10

b) We cannot conclude that the weights before and after the diet are different. B) a) S = 11 b) We can conclude that the weights before and after the diet are different. C) a) S = 10 b) We can conclude that the weights before and after the diet are different. D) a) S = 11 b) We cannot conclude that the weights before and after the diet are different. 22) Given n1 = 18, n2 = 27, S = 398, and H 1 : m 1 < m 2 , compute s. A) 414

B) 43.16

C) 56

22) D) -0.37

23) A sample of eight people attended a two day course that prepares students for college

admission testing. The students were given a pretest before the course and a posttest after the course. The results were as follows. Student 1 2 3 4 5 6 7 8 Pretest 66 74 74 71 70 72 65 66 Posttest 79 76 63 67 64 89 78 74 a) Compute the test statistic b) Can you conclude that the median scores differ between the pretest and posttest? Use the = 0.10 level of significance. A) a) S = 9

b) We can conclude that the median of the pretests and posttests are different. B) a) S = 10 b) We can conclude that the median of the pretests and posttests are different. C) a) S = 10 b) We cannot conclude that the median of the pretests and posttests are different. D) a) S = 9 b) We cannot conclude that the median of the pretests and posttests are different.

23)

24) The following data was collected as part of a study examining whether there is a

24)

difference between the number of hours men and women watch television. The values represent the number of hours a subject watched television on a designated Tuesday night. In the process of computing the test value the data from both samples should be combined, arranged in order, and ranked according to each group. Calculate the sum of the ranks for both groups. Lower values rank ahead of higher ones. Men 2.0 1.5 3.0 2.5 2.0 1.0 0.0 2.0 1.5 2.5 2.0 2.0 Women 2.0 2.5 1.0 1.0 1.5 2.5 2.0 1.0 2.0 1.5 1.0 0.0 A) The sum of the ranks for the men is 137.5, and the sum of the ranks for the woman is 162.5. B) The sum of the ranks for the men is 170, and the sum of the ranks for the woman is 130. C) The sum of the ranks for the men is 162.5, and the sum of the ranks for the woman is 137.5. D) The sum of the ranks for the men is 130, and the sum of the ranks for the woman is 170. 25) For the following data, compute the test statistic and the critical value, and determine

whether to reject H 0 at the

25)

= 0.05 level.

Sample A 69 60 68 64 78 65 60 76 60 75 Sample B 59 41 68 59 84 65 46 84 48 61 A) S = 5, Critical value is 8, Do not reject H 0 B) S = 4, Critical value is 4, Do not reject H 0 C) S = 4, Critical value is 4, Reject H 0 D) S = 5, Critical value is 8, Reject H 0 26) Given n1 = 16, n2 = 21, S = 249, and H 1 : m 1 < m 2 , find the P-value. A) 0.0455

B) 0.0228

C) 0.9545

26) D) 0.0910

27) The following data was collected as part of a study examining whether there is a

27)

difference between the number of hours men and women watch television. The values represent the number of hours a subject watched television on a designated Tuesday night. Lower values rank ahead of higher ones. Men Women

2.0 2.0

1.5 2.5

3.0 1.0

2.5 1.0

2.0 1.5

1.0 2.5

0.0 2.0

2.0 1.0

1.5 2.0

2.5 1.5

2.0 1.0

2.0 0.0

a) Calculate the P-value. b) Can you conclude that the median times watching television are different? Use the = 0.10 level of significance. A) a) 0.1251

b) Yes, you can not conclude that the median times are different. B) a) 0.2502 b) No, you can not conclude that the median times are different. C) a) 0.1251 b) No, you can not conclude that the median times are different. D) a) 0.2502 b) Yes, you can not conclude that the median times are different. 28) Six second-graders tried tossing a ball into a basket ten times each. Their teacher then

suggested a different way of tossing the ball, and the six students tried again. The number of successful tosses, before and after the teacher's suggestion, are shown below. Student Before the suggestion (out of 10) After the suggestion (out of 10)

A 2 4

B 4 4

C 5 2

Compute S, the test statistic for a signed-rank test. A) S = 2 B) S = 3 C) S = 7

D 2 4

E 5 2

F 4 4

D) S = 6

28)

ESSAY. Write your answer in the space provided or on a separate sheet of paper. 29) Heart rates, in beats per minute, were measured for samples of 12 track athletes and 15 swimmers. The

results are shown below. Can you conclude that the median heart rate is greater for swimmers than for track athletes? Use the = 0.05 level of significance. Use a rank-sum test. Track 68 62 65 72 70 68 64 77 77 66 72 76 Swim 82 81 71 69 79 65 66 70 80 78 75 82 75 63 79 i. State the null and alternate hypotheses. ii. Compute teh value of the test statistic. iii. Compute the P-value. iv. State a conclusion. 30) Battery lifetimes, in hours, were measured for two types of batteries commonly used in laptop

computers. Twelve batteries of one type and 13 of another type were tested. The results are shown below. Can you conclude that the lifetimes differ between the two types of batteries? Use the = 0.01 level of significance. Use a rank-sum test. Type A 4.1 6.8 5.8 5.2 3.2 2.5 3.9 2.1 4.9 5.2 2.1 4.0

Type B 6.7 4.1 5.6 7.0 3.1 2.3 4.6 3.8 4.4 4.9 7.1 4.7 4.0

i. State the null and alternate hypotheses. ii. Compute teh value of the test statistic. iii. Compute the P-value. iv. State a conclusion.

Answer Key Testname: C15

1) C 2) a. H 0 : m = 1100; H 1 : m < 1100

b. -2.500 c. -1.645 d. Reject H 0 . 3) a. H 0 : m = 25; H 1: m

b. 5 c. 3 d. Do not reject H 0. 4) a. H 0 : m = 55; H 1: m > 55

b. 5 c. 6 d. Reject H 0 . 5) a. z = -1.64

b. No c. No 6) a) H 0 : m 1 = m 2 , H 1 : m 1 < m 2

b) z = -1.52 c) 0.0643 d) Do not reject H 0 7) D 8) A 9) A 10) C 11) D 12) B 13) C 14) D 15) C 16) B 17) A 18) D 19) C 20) B 21) A 22) B 23) C 24) B 25) D 26) A 27) B 28) B

Answer Key Testname: C15

29) i. H 0: m 1 = m 2, H 1: m 1 < m 2

ii. -1.88 iii. 0.0301 iv. Reject H 0. 30) i. H 0: m 1 = m 2, H 1: m 1

ii. -0.90 iii. 0.3682 [Tech 0.3695] iv. Do not reject H 0.