MAT 300 Unit 1 Challenges Sophia MAT300 Unit 1 Challenges Sophia

MAT 300 Unit 1 Challenges Sophia Click below link for Answers https://www.sobtell.com/q/tutorial/default/206484-mat-300-unit-1-challenges-sophia https://www.sobtell.com/q/tutorial/default/206484-mat-300-unit-1-challenges-sophia

Challenge 1 A survey on Internet usage was conducted among a group of 200 students in the school cafeteria. It was found that 100 students spend at least two hours online every day.

Which of these is an example of descriptive statistics? a.)

50% of the students surveyed spend at least two hours online each day. b.)

50% of the students in the cafeteria spend at least two hours online each day. c.)

50% of the students in a class spend at least two hours online each day. d.)

50% of the students in the school spend at least two hours online each day.

Recall that descriptive statistics simply notes what we find in some samples. Since we are simply noting how many people in the survey spend at least two hours on the Internet, this is a descriptive statistic about the survey.

A company packed 8 dark chocolates in a box of 32 assorted chocolates.

Which of these does NOT represent inferential statistics? a.)

25% of the chocolates manufactured in a factory are dark chocolates. b.)

25% of the chocolates packed in a day are dark chocolates. c.)

25% of the chocolates in a box are dark chocolates. d.)

25% of the chocolates manufactured in a batch are dark chocolates.  Recall that inferential statistics allows us to make inferences about a population based on some sample value. So noting that there are 25% of chocolates in a box is an example of a descriptive statistic. If we were to use that information to make broader inference, then it would be inferential.

A bakery owner asked 150 customers to taste a new type of cookie and found that 60 people liked its taste.

Which of these is an example of descriptive statistics? a.)

40% of the people in the city where the bakery is located like the taste of the cookie. b.)

40% of all the bakery's customers like the taste of the cookie. c.)

40% of the surveyed customers like the taste of the cookie. d.)

40% of all people like the taste of the cookie.  Recall that descriptive statistics simply notes what we find in some sample. So noting that 40% of the people sampled in the survey like the taste is simply a descriptive statistic of what was found in that survey.

If numbers collected from a survey are measurements, what are these measurements called before you perform any calculations? a.) biased data b.) peer-reviewed data c.) raw data d.) available data  Since no operations are performed, the data is simply raw data.

You find some public records about customer satisfaction in the company's archive.

What type of data is this called? a.) raw data b.) biased data c.) available data d.) peer-reviewed data  Since the data is already collected and public record it would be considered available data.

If you are using new information in a survey that was not collected during previous surveys, you will be using _______ to gauge customer satisfaction. a.) available data

b.) raw data c.) biased data d.) peer-reviewed data  Recall that raw data is typically not previously available. Since the information from this survey had not been made available from previous surveys, you are using a form of raw data.

Select the two categories that would yield quantitative data. a.)

Age of pet b.)

Type of pet c.)

Gender of pet d.)

Color of pet e.)

Weight of pet Answer Rationale Age and weight can only be expressed with numbers. Therefore, these are examples of quantitative data. Type of the pet (fish, dog, etc), color of the pet (brown, black, etc.), and gender of the pet can only be put into categories. Therefore, these are examples of qualitative data instead of quantitative data.

Select the two categories that would yield qualitative data. a.)

Age of pet b.)

Pet owner's monthly income c.) of Type pet d.)

Pet's purchase price e.)

Color of pet Answer Rationale Recall that qualitative data can only be put into categories. The type of pet (dog, cat, etc.) and the color of the pet (brown, black, etc.) can only be put into categories and can only yield qualitative data. The price of the pet ($5, $75, etc.), the age of the pet (2 years, 6 years, etc.), and the pet owner's monthly income ($1,500, $2,100, etc.) can only be expressed with numbers. Therefore, these are examples of quantitative data instead of qualitative The amount spent on pet food each month is an example of _____ data. a.) ordinal b.) nominal

c.) qualitative d.) quantitative  Since the amount spent on a pet can only be expressed with numbers, it is considered quantitative data.

Which of these data sets represent continuous data? a.)

Number of questions answered correctly in a multiple-choice quiz b.)

Numbers of tickets sold for a football game c.)

Heights of members of a baseball team d.)

Monthly salaries of employees  Since height can take on any value inside an interval, measuring the heights of each team member would create a continuous data set.

Which of these data sets does NOT represent continuous data? a.)

Weights of potatoes in a sack b.)

Rainfall readings during a week c.)

Heights of trees at a nursery d.)

Gender of students in a college  Recall that gender is qualitative because it can only take a certain number of values ( male, female). So gender of college students cannot be continuous data.

Which of these data sets represent discrete data? a.)

Snowfall that fell last night in Maine b.)

Time spent in running 1 mile c.)

Temperature readings for Tuesday afternoon d.)

Number of questions answered incorrectly in a multiple-choice quiz  Recall that discrete data can only take on a set number of values in an interval. In a multiplechoice quiz, the total number of correct answers must be something like 0, 1, 2, etc. Tallying the number of incorrect answers would create a discrete data set.

CHALLENEG 2

A dealership is trying to understand its customers better. A survey was conducted among 100 customers to determine their favorite color for a sedan.

Which statement is true? a.)

All people who purchased a car from the car dealer represent the sample. b.)

The 100 people surveyed represent the population. c.)

All people who purchased a car from the car dealer last year represent the population. d.)

The 100 people surveyed represent the sample.

Since the car dealership didn't survey all of their customers, but only a subset of them, the 100 people surveyed would be considered a sample A researcher is interested in researching weekly earnings in large cities across the country. A survey was conducted among 100 residents in a city to determine their weekly earnings.

Which statement is true? a.)

The surveyed residents are the population. b.)

The surveyed residents are the sample. c.)

The residents in the city are the population. d.)

The residents in the city are the sample. c.)Incorrect.

Recall the researcher wants to understand large cities across the country. So the population would be all residents in all large cities across the country, not simply the one city where the survey was conducted.  The 100 residents in a city represent a subset of all residents in large cities. So they are a sample.

A production company is interested in collecting information on the impact of an educational documentary on everyone that watched it at the film festival.

Which statement is true? a.)

The group of people that watched the documentary at the festival is the sample. b.)

The production company is the sample. c.)

The group of people that watched the documentary at the festival represents the population. d.)

The production company represents the population. 

The population is the entire set of interest, which would be all the people who attended this film festival.

Which of these random samples qualifies as a representative sample if studying the opinion of people who use online shopping websites? a.)

Consumers who order products online b.)

Employees of the online shopping websites c.)

Consumers who do not shop online d.)

Retailers who sell their products online b.)Incorrect.

Recall that the study is designed to collect information on online shoppers. A sample of employees of online shopping websites, even if they shop online, would not be a representative sample of all online shoppers.  Since the purpose of the study is to understand people who use online shopping websites, the representative sample comes from those actually making online purchases.

Which of these random samples qualifies as a representative sample if studying the opinion of the attendees to a business seminar? a.)

35 people whose businesses are related to the topics discussed at the seminar b.)

35 people who attended the seminar c.)

35 people who spoke at the seminar d.)

35 people from the company that organized the seminar d.)Incorrect.

Since those who organized the seminar may be different from the attendees, they are not going to be representative since the study wants to understand the opinions of those who attended the seminar.

For the sample to be representative, it should be regarding those who attended the seminar since the purpose of the study is to understand the opinion of those who attended the seminar.

So the 35 people whose opinions are gathered and who attended the seminar are a representative sample.

Which of these random samples qualifies as a representative sample to find out what parents think about the levels of college tuition fees in the state? a.)

50 residents of a county in the state b.)

50 parents of college students from the state c.)

50 residents of a city in the state d.)

50 parents of college students from another state  Recall the study wants to understand what parents think about levels of tuition in the state. So to be representative, the sample needs to be parents of students who are enrolled in the state.

Which of these is an example of a systematic random sample? a.)

Picking out 10 names from a bag containing names of 50 students. b.)

Selecting all the students in a class of 30. c.)

Selecting every 20th person in a line of 200 moviegoers. d.)

Selecting 4 balls from a bag containing 20 balls.  Since you are choosing every 20th person in line instead of selecting 10 people at random, you are gathering a systematic random sample.

Which of these is an example of systematic random sample? a.)

Picking out the telephone number of every 20th person from a directory. B Choosing 10 marbles from a jar containing 40 marbles. c.)

Picking out 10 names from a group of 50 students. d.)

Selecting one card from a deck of 52 well-shuffled cards. c.)Incorrect.

Since there is no fixed or systematic method is used, it cannot be a systematic sample.  Since every 20th person is picked from a directory, it is systematic.

L, Which of these examples best represents a simple random sample? a.)

Using a name generator to pick out 20 names from a group of 100 students. b.)

Picking out the names of every 10th person from a group of 200 people who drive a car. c.)

Selecting all the students in a group of 50 students. d.)

Selecting every 15th person in a group of 100 volunteers. 

Since the name generator is not systematically choosing names, but simply choosing them arbitrarily or randomly, this example best represents a simple random sample.

Which of these statements best explains cluster sampling? a.)

In the cluster sampling method, total population is roughly divided into groups based on location and a simple random sample of the groups is taken. b.)

In the cluster sampling method, population is broken into groups and then elements are randomly selected in proportion from each group. c.)

In the cluster sampling method, elements are randomly selected from the total population. d.)

The cluster sampling method is a combination of random sampling techniques.  Recall that for cluster random sampling, the elements of a sample need to be divided into groups by space and then have random samples from Which of these statements best defines a stratified random sample? a.)

It is a sample where every nth element of the population is selected in a sequence. b.)

It is a sample where the population is divided into roughly equal groups, and then elements are randomly selected from each group. c.)

It is a sample in which every element has the same chance of being selected from the total population. d.)

It is a sample where the population is first broken into homogenous groups and then elements are randomly selected, in proportion, from each group. a.)Incorrect.

If every element of the sample is selected in sequence, this is a systematic sample.  Recall that for something to be a stratified random sample, the population needs to be divided into homogenous groups with random samples drawn from each group.

Select the statement regarding cluster sampling that is FALSE. a.)

Every element of the total population has an equal probability of being selected. b.)

Some of the groups are randomly selected. c.)

The total population is divided into groups. d.)

Every element of some groups is included in the sample. 

Recall that if every element of the population has an equal probability of being selected, that is referred to as a simple random sample.

Which of these is an example of multi-stage sampling? a.)

Dividing the total population of New York into groups and then selecting people in proportion from these groups. b.)

Choosing New York as a sample, then selecting a sample of zip codes within New York, then sampling the names of people living in those zip codes. c.)

Randomly selecting elements from the entire population of New York d.)

Dividing the population of New York into groups and then making simple random samples from those groups. a.)Incorrect.

Dividing the population into homogeneous groups and then sample is only one stage and is an example of stratified random sampling instead of multi-stage sampling.  Since the sample has multiple stages at the state, zip, and then finally the names of people, this would be an example of a multi-stage sampling design.

CHALLENEG 3 Select the statement that expresses an approach used with experiments. a.)

The researcher should have control over all of the variables. b.)

The researcher should have control over exactly one variable. c.)

The researcher should have control over some of the variables. d.)

The researcher should not have control over any variable.  Recall in an experiment that researchers can impose treatments. So they effectively have control over some conditions and variables in the study.

Select the statement that expresses an approach used with observational studies. a.)

“You took all those notes. You recorded customer counts, menus, food prices, even the general atmosphere of the food truck environment.” b.)

None of the above c.)

We can test out locations for a brick and mortar by moving our truck. I mean, we have our social media page that gives our daily locations, but what if we found a location we like for a brick and mortar and see if our customers follow us there? d.)

I think asking questions and collecting the information we want from our population sample is a good start. d.)Incorrect.

This statement describes sampling and designates neither an observational study nor an experiment.  Since you are simply recording information on the food truck environment without controlling anything, this approach is typical of observational studies.

Which of the following is an advantage that is unique only to experiments? .) a Experimenters can use the data to draw cause and effect relationships. b.)

Experimenters can use sample data to draw inferences about the population. c.)

Experimenters can observe and record information of interest. d.)

Experimenters can work with a sample that represents the population as a whole. d.)Incorrect.  Since there is a random assignment of participants to both the treatment and control groups, in general, experiments can usually make strong cases for causality when analyzing the data.

If you were to track coffee preferences among your co-workers for the next two weeks, which type of statistical study would you be performing? a.) prospective study b.) case control study c.) retrospective study d.) experiment c.)Incorrect.

A retrospective study means going backwards in time from a given time point.  If you are tracking the tendencies of participants moving forward, in this case tracking coffee preferences among co-workers for a two-week period, you are performing a prospective study.

Which of these situations best describes a retrospective observational study? a.)

A clinical researcher giving a medicine to a person and analyzing its effects. b.)

A doctor analyzing the medical history of a person. c.)

A student flipping a coin and analyzing its outcomes. d.)

A company using different promotions and analyzing its sales. )Incorrect.

Since the student is flipping the coin and gathering information, this situation best describes a prospective observational study.  Since the doctor went back in time and simply analyzed the medical history of a person without putting in any controls, this situation best describes a retrospective observational study.

Following a group of truck drivers and noting the number of miles traveled for one year refers to which type of statistical study? a.)

Case control study b.)

Retrospective study c.)

Experiment d.)

Prospective study  Since they followed drivers and gathered information moving forward, this situation best describes a prospective observational study.

Which of these is true for the control group in an experiment? a.)

It is exposed to the factor under consideration and all other external influences are held constant. b.)

It is not exposed to the factor under consideration and all other external influences are varied. c.)

It is not exposed to the factor under consideration and all other external influences are held constant. d.)

It is exposed to the factor under consideration and all other external influences are varied.  In experimental design, recall that the control for the experiment is not assigned a treatment and confounding influences are controlled for so we can distinguish observable differences between groups.

Which of these situations best describes randomization? a.)

Drawing a black card from a well-shuffled standard deck of 52 cards. b.)

Changing the number of coins used in an experiment involving coin tosses.

c.)

Repeating the same cancer treatment for 100 patients to get a larger sample. d.)

Regulating the amount of sunlight that enters a greenhouse.  Since the assignment is performed by the random process of drawing cards from a wellshuffled deck, this process describes randomization.

Analyzing the results of rolling a fair die 100 times refers to which of these principles? a.)

Replication b.)

Treatment c.)

Control d.)

Randomization  Since the process involves examining the results of rolling a die, this describes replication.

Which of these statements is NOT true regarding a randomized block design experiment? a.)

Elements are randomly selected from equal-sized blocks of the total population. b.)

The sample is divided into participants or subjects and then grouped by a variable of interest. c.)

The elements are randomly allocated to treatment and control groups. d.)

This design has an advantage of controlling for variables that might confound the response.  Recall that for randomized block design, the elements are first divided into homogenous groups, like age or gender, and are not necessarily equally sized.

Which of these statements best describes a randomized block design experiment? a.)

In this experiment, the subjects are divided into groups by a variable of interest and the elements are then randomly allocated to treatment and control groups within these groups. b.)

In this experiment, a sample is divided roughly into some groups and then some of the groups are randomly selected. c.)

In this experiment, closely matched elements are paired, and then one of them is put in the treatment group and the other in the control group. d.)

In this experiment, the subjects are divided into homogeneous blocks and a treatment is assigned to every element of the block.

Recall that in a randomized block design the experiment is run within each block. So the treatment and control would be done within the blocks.

Which of these statements is true regarding a randomized block design experiment? a.)

The total population is randomly divided into groups of equal size and a treatment is assigned to each group. b.)

The probability of every element being selected from the total population is the same. c.)

Every nth element is selected out of the total population. d.)

Random allocation of treatment and control groups is done within the divided groups.  Recall that in a randomized block design, the experiment is run within each block. So the treatment and control would be done within the blocks.

Select the FALSE statement about completely random design. a.)

This design can lead to disproportionate results. b.)

This design is the easiest way of assigning individuals to a treatment group. c.)

The test subjects are assigned to treatment levels of the primary factor at random. d.) variable The test subjects are first broken into groups based on a certain of interest before being assigned to each treatment condition.  If variables are broken down into groups by a variable of interest, this is representative of a block design.

Select the TRUE statement for completely random design. a.)

The experimental units are assigned randomly to exactly one control group and one or more treatment groups. b.)

The experimental units are assigned randomly to one or more control groups and one or more treatment groups. c.)

The experimental units are assigned randomly to exactly one control group and one treatment group. d.)

The experimental units are assigned randomly to one or more control groups and exactly one treatment group. c.)Incorrect.

This statement is FALSE, because recall that the completely randomized design allows for the possibility of one or more treatments.  If we have a completely randomized design, we have one control and it allows for one or more treatment groups.

Select the FALSE statement about completely random design. a.)

The additional variables affect different control groups differently. b.)

Any number of treatments may be addressed. c.)

It minimizes the effects of confounding variables. d.)

Subjects are randomly assigned to treatments. d.)Incorrect.

This statement is TRUE since subjects are randomly assigned to treatment and control.  Since there is a completely random design, we expect one control group.

Which of these statements about a matched-pair design is FALSE? a.)

Possible confounding variables are controlled by matching as many characteristics as possible. b.)

The matched pair must contain two distinct subjects. c.)

Elements within each pair are randomly selected. d.)

Treatments are randomly applied to one element of each pair.  In the matched pair design it is possible to be your own control. An example might be a before-and-after trial.

Which of these statements is true for a matched-pair design? a.)

The matched elements within different pairs are randomly assigned to the same treatment. b.)

The matched elements within each pair are randomly assigned to different treatments. c.)

The matched elements within different pairs are randomly assigned to different treatments. d.)

The matched elements within each pair are assigned to the same treatment. d.)Incorrect.

This statement is FALSE because in the matched-pair design, the elements within the pair are assigned to different treatments.  Recall that the matched-pair design randomly assigns the treatment within the pair.

Which of these statements best describes a matched-pair design? a.)

A design in which the total population is randomly divided into groups of equal size and a treatment is assigned to each group. b.)

A design in which the total population is divided into homogeneous blocks and a treatment is assigned to every element of the block. c.)

A design in which an entire sample is divided into pairs, and then the pairs are matched together at random. d.)

A design in which only two treatments are tested on pairs of similar subjects.  Recall that matched pairs test treatments on subjects that are matched because they have similar characteristics, such as age or gender.

Which of the following is NOT an example of a survey? a.)

A cell phone company randomly called 200 customers and asked about customer satisfaction. b.)

Every 50th person listed in a neighborhood directory was emailed and asked about their favorite genre of music. c.)

A high school student council is determining the new mascot for the school. Five students from each grade are asked what they would want as the mascot. d.)

A nutritionist is studying the relationship between eating carbohydrates and gaining weight.

The nutritionist recorded the diets and weights of 10 people for a year.

This is an example of a prospective study. There was no survey component since the researcher gathered the information without asking people in the study.

Which of the following is an example of a survey? a.)

A clothing store owner asks questions to collect information from the population by taking a sample of his customers. b.)

A food truck owner tests out different locations for a brick and mortar by using the business's Facebook page to promote the daily location. c.)

An owner of a local pizza shop offers two new toppings to see which sells the most at the end of the day. d.)

A general manager of a restaurant records customer counts and food prices to determine what changes need to be made. c.)Incorrect.

Since there is not an instrument provided to people to gather information or ask questions, it is not an example of a survey.  Since we are asking questions to gather information, this is an example of a survey.

Which of these represents a blind experiment? a.)

Asking a group of children to choose their favorite toy from a bin containing different toys. b.)

Asking a group of students to choose their favorite field trip location from a list of five field trip options. c.)

Asking a group of adults to compare the taste of coffee without revealing the names of the brands. d.)

Asking a group of students about their favorite TV show from a list of eight TV shows.  Since the brands are not revealed to those comparing the coffee, we say they are blinded from the study participants.

Which of these is an example of a blind experiment? a.)

Asking a group of students to compare the tastes of different brands of potato chips without revealing the names of the brands. b.)

Asking a group of kids to choose their favorite candy from a jar containing different candies. c.)

Asking a group of students about the candidate they will vote for in the school elections. d.)

Asking a group of students about their favorite sports from a list containing names of 10 sports.  The brands are not revealed to the students, so we say they are blinded to the respondents.

Which of these represents a blind experiment? a.)

Asking a group of adults about the candidate they will vote for in the presidential elections. b.)

Asking a group of car drivers to choose their favorite car from a list of 10 cars. c.)

Asking a group of girls to compare the tastes of chocolate without revealing the names of the brands. d.)

Asking a group of students about their favorite movie from a list of five movies.  Since brands of chocolates are not revealed to the girls, we say they are blinded.

By accident, Janae has been making decaffeinated coffee for her co-workers for the entire week. But some of her co-workers have claimed that the extra boost of caffeine has helped them focus on their work.

What does the placebo effect mean in this specific situation? a.)

The benefit is the result of the "control" (coffee, although decaffeinated) and not an effect of the "active ingredient" (caffeine). b.)

The benefit is due to the fact that the co-workers are given a "treatment" (coffee, although decaffeinated) and not an effect of the "active ingredient" (caffeine). c.)

The benefit is the result of the fact that the "treatment" (coffee, although decaffeinated) contains another "active ingredient" besides caffeine.

By accident, Janae has been making decaffeinated coffee for her co-workers for the entire week. But some of her co-workers have claimed that the extra boost of caffeine has helped them focus on their work.

What does the placebo effect mean in this specific situation? a.)

The benefit is the result of the "control" (coffee, although decaffeinated) and not an effect of the "active ingredient" (caffeine). b.)

The benefit is due to the fact that the co-workers are given a "treatment" (coffee, although decaffeinated) and not an effect of the "active ingredient" (caffeine). c.)

The benefit is the result of the fact that the "treatment" (coffee, although decaffeinated) contains another "active ingredient" besides caffeine.

By accident, Janae has been making decaffeinated coffee for her co-workers for the entire week. But some of her co-workers have claimed that the extra boost of caffeine has helped them focus on their work.

What does the placebo effect mean in this specific situation? a.)

The benefit is the result of the "control" (coffee, although decaffeinated) and not an effect of the "active ingredient" (caffeine). b.)

The benefit is due to the fact that the co-workers are given a "treatment" (coffee, although decaffeinated) and not an effect of the "active ingredient" (caffeine). c.)

The benefit is the result of the fact that the "treatment" (coffee, although decaffeinated) contains another "active ingredient" besides caffeine. D .The co-workers get a benefit from the "treatment" (coffee, although decaffeinated) since they also drink coffee at the coffee shop across the street during breaks.  Recall the placebo effect simply means the responders elicit a response even though they don't receive any treatment. Since her co-workers were not receiving additional caffeine but claimed to get a boost from the decaffeinated coffee, this would be the placebo effect.

Julie had a sore throat and was told she was being given a name brand medicine but it was really colored water. Four hours later she was asked if she feels better, and she agreed she did.

What does the placebo effect mean in this specific situation? a.)

Julie received the benefit from the treatment since she also took sore throat medication. b.)

The benefit is due to the fact that Julie was given the treatment (liquid, although water) and not an effect of the "active ingredient" (cough medicine). c.)

The benefit is that Julie was given the control (liquid, although water) and not the active ingredient (cough medicine). d.)

The benefit is the fact that Julie received the treatment (liquid, although water) and it contains another active ingredient. .)Incorrect.

The benefit would be the fact that Julie had said she felt better.  Since Julie didn't receive an active treatment and said that she felt better, this is what is required to elicit a placebo effect.

Jennifer had a headache and was told she was given a name brand medicine but it was really a sugar pill. Three hours later she was asked if she feels better, and she agreed she did.

What does the placebo effect mean in this specific situation? a.)

The benefit is that Jennifer was given the control (pill, although only a sugar pill) and not the active ingredient (cough medicine). b.)

Jennifer received the benefit from the treatment since she also took a nap. c.)

The benefit is due to the fact that Jennifer was given the treatment (pill, although only a sugar pill) and not an effect of the "active ingredient" (headache medicine). d.)

The benefit is the fact that Jennifer received the treatment (pill, although only a sugar pill) and it contains another active ingredient.

Correct.

Since there was no active ingredient in the pill but Jennifer thought that her headache went away. This is what is required for a placebo effect.

CHALLENEG 4 The following are the Consumer Price Index (CPI) for the years 1995-1997. All of the values use a reference year of 1990.

Year: 1995; CPI: 114 Year: 1996; CPI: 128 Year: 1997; CPI: 143 Which of the following is true about the CPI, based on the information? a.) $100 in 1995 would have been worth $114 in 1990. b.) $100 in 1996 would have been worth $100 in 1995. c.) $100 in 1990 would be equivalent to $143 in 1997. d.) $100 in 1997 would be equivalent to $143 in 1996. )Correct.

Since the base year is 1990, it would have a value of 100. We want to convert from 1990 to 1997.

So $100 in 1990 is like having $143 in 1997. Another way of saying this is that if something costs $1 in 1990, it would cost $1.43 in 1997.

The following are the Consumer Price Index (CPI) for the years 1991-1993. All of the values use a reference year of 1986.

Year: 1991; CPI: 110 Year: 1992; CPI: 120 Year: 1993; CPI: 135 Which of the following is true about the CPI, based on the information? a.) $100 in 1986 would be equivalent to $135 in 1993. b.) $100 in 1991 would have been worth $110 in 1986. c.) $100 in 1993 would be equivalent to $120 in 1992. d.) $100 in 1992 would have been worth $100 in 1986.

Correct.

Since the base year is 1986, it would have a value of 100. We want to convert from 1986 to 1993.

So $100 in 1986 is like having $135 in 1993. Another way of saying this is that if something costs $1 in 1986, it would cost $1.35 in 1993.

The following are the Consumer Price Index (CPI) for the years 1990-1992. All of the values use a reference year of 1985.

Year: 1990; CPI: 114 Year: 1991; CPI: 130 Year: 1992; CPI: 145 Which of the following is true about the CPI, based on the information? a.) $100 in 1985 would be equivalent to $145 in 1992. b.) $100 in 1992 would be equivalent to $130 in 1991. c.) $100 in 1990 would have been worth $114 in 1985. d.) $100 in 1991 would have been worth $100 in 1990.

Since the base year is 1985, it would have a value of 100. We want to convert from 1985 to 1992.

So $100 in 1985 is like having $145 in 1992. Another way of saying this is that if something costs $1 in 1985, it would cost $1.45 in 1992.

A recent survey supports the idea that people who like strong flavor end up drinking more coffee. The only thing that worries the researcher is that she distributed the survey right before a holiday weekend, so she did not receive as many responses as she would have hoped.

Determine the confounding variable in the researcher's experiment. a.) the holiday weekend b.) the rate of coffee consumption c.) people who like strong flavor d.) coffee temperature  Since the researchers didn't account for the holiday weekend in the study, this would be considered a confounding variable.

Sean wants to investigate the effect of temperature on the rate of a chemical reaction.

What type of variable is the temperature in Sean's experiment? a.)

Confounding b.)

Dependent c.)

Explanatory d.)

Response  Recall that an explanatory variable is a variable that we believe is predictive of something else. Since temperature is what is affecting rate of chemical reaction, it is the explanatory variable.

When Ben increases the temperature difference between two junctions, the voltage also increases.

What type of variable is voltage in the above situation? a.)

Response b.)

Confounding c.)

Independent d.)

Explanatory d.)Incorrect.

Recall that an explanatory variable is when an increase in that particular variable will correspond to an increase or decrease in some other variable. In this case, temperature is the explanatory variable because it is increasing between different junctions.  Since the voltage is the outcome being measured, we refer to this as the response variable.

Incorrect Which of these represents a binomial question? a.)

How many animals do you own? b.)

Do you own a rabbit? c.)

What are the names of your pets? d.)

How does being a pet owner make you feel?  Since there are only two responses (yes or no), it is a binomial question.

Which of these represents a closed question? a.)

Will this information help you?

b.)

How will this information help you? c.)

What information do you need? d.)

What will this information help you do? c.)Incorrect.

Recall that closed questions produce a limited number of answer choices. Since responders might all respond differently and can respond how they want, this would be an open question type.  Since we only expect that responses will be yes or no, then there should be a limited number of responses to expect. Therefore, this question represents a closed question.

Which of these represents an open question? a.)

HOW can I help you? b.)

Can I help you? c.)

Will this help you? d.)

Who helped you? b.)Incorrect.

Recall that open questions can produce any number of responses. Since the question "Can I help you?" generally elicits only two responses -- yes or no -- this is an example of a closed question.  Since the responder can choose how they can be helped, this is an open question.

After reading a survey in Modern Dog Magazine that reported that 74% of Americans prefer dogs, Kendra is curious about the survey's reliability. She finds out that the study used an outside research organization to select 1,000 people each year for seven years. The results from each year are below.

Year 1: 75% Year 2: 76% Year 3: 79% Year 4: 73% Year 5: 71% Year 6: 74% Year 7: 71% Select the statement that is true about Modern Dog Magazine's survey. a.)

The survey results are accurate but not precise. b.)

The survey results are precise but not accurate.

C’ The survey results are neither accurate nor precise. d.)

The survey results are both accurate and precise.  To be accurate and precise they should be around 74% for all the measures. We can see that they are all relatively close to one another (between 71% and 79%), so they are precise. They are also all close to 74%, so they are accurate.

The American Kennel Club sponsored a national survey of 5,000 households that own pets and found that 74% of households prefer dogs.

The next week, Kendra conducts an informal poll, asking every person that comes into the store if they prefer dogs to other animals. On Sunday, she enters the following information into an Excel spreadsheet: Monday: 94% Tuesday: 87% Wednesday: 89% Thursday: 95% Friday: 91% Saturday: 93% Sunday: 89% Select the statement that is true about Kendra's measurements. a.)

Kendra's measurements are both accurate and precise. b.)

Kendra's measurements are accurate but not precise. c.)

Kendra's measurements are neither accurate nor precise. d.)

Kendra's measurements are precise but not accurate.  To be accurate and precise they should be around 74% for all the measures. Since the measures are close to each other (87% to 95%), they are precise. However, given that the values are far from the 74%, they are not accurate.

Kendra reads in Modern Dog Magazine that the average age of dogs currently alive is 4.8 years. To determine if this finding applies to the customers in her pet store, Kendra surveys every fifth customer in her store who owns a dog and asks the age of their dog. She collects data for seven weeks and obtains the following averages.

Week 1: 3.7 years Week 2: 3.8 years Week 3: 4.2 years Week 4: 4.1 years Week 5: 3.9 years Week 6: 3.9 years Week 7: 4.0 years

Select the statement that is true about Kendra's sample. a.)

Kendra's samples are neither accurate nor precise. b.)

Kendra's samples are both accurate and precise. c.)

Kendra's samples are precise but not accurate. d.)

Kendra's samples are accurate but not precise.  To be accurate and precise they should be around 4.8 for all the measures. We can see that they are all relatively close to one another (between 3.7 and 4.2), so they are precise.

However, they are all are smaller than 4.8, so they are not accurate.

In 2014, there were 500 students enrolled in a college course. In 2015, there were 450 students enrolled in this particular course.

Select the true statement about students enrolled in this course from 2014 to 2015.

Percentages are rounded to the nearest tenths place. a.)

The absolute change is -50 students and the relative change indicates a decrease of 10%. b.)

The absolute change is 50 students and the relative change indicates a decrease of 10%. c.)

The absolute change is –50 students and the relative change indicates a decrease of 11%. d.)

The absolute change is 50 students and the relative change indicates an increase of 11%.

The absolute difference, or absolute change, is new value minus old value. The new value from 2015 is 450 students and the old value from 2014 is 500 students. So the absolute difference is: The relative change is the absolute difference divided by the initial value of 500 students:

In 2011, there were 150 participants in a quiz competition. In 2012, there were 185 participants in this quiz competition.

Select the true statement about participants in the quiz competition from 2011 to 2012.

Percentages are rounded to the nearest tenths place. a.)

The absolute change is -35 students and the relative change indicates a decrease of 35%. b.)

The absolute change is -35 students and the relative change indicates a decrease of 23.3%. c.)

The absolute change is 35 students and the relative change indicates an increase of 23.3%. d.)

The absolute change is 35 students and the relative change indicates an increase of 18.92%.

 The absolute difference, or absolute change, is new value minus old value. The new value from 2012 is 185 participants and the old value from 2011 is 150 participants. So the absolute difference is: The relative change is the absolute difference divided by the initial value of 150 participants: Incorrect Go to the Next Question I need help with this question In 2000, there were 4,578 residents living in multi-family housing units. In 2010, there were 4,312 residents living in multi-family housing units.

Select the true statement about residents living in multi-family housing units from 2000 to 2010. Percentages are rounded to the nearest tenths place. a.)

The absolute change is -266 residents and the relative change indicates a decrease of 5.8%. b.)

The absolute change is -266 residents and the relative change indicates a decrease of 6.2%. c.)

The absolute change is 266 residents and the relative change indicates an increase of 5.8%. d.)

The absolute change is 266 residents and the relative change indicates an increase of 6.2%.

The absolute difference, or absolute change, is new value minus old value. The new value from 2010 is 4,312 residents and the old value from 2000 is 4,578 residents. So the absolute difference is: The relative change is the absolute difference divided by the initial value of 4,578 residents:

A company’s market share went from 50 to 65 percent of the total market.

Of the following choices, which two statements about the company's market shares are true? a.)

There was a 23% increase in market shares. b.)

There was a 30% increase in market shares. c.)

Market shares rose by 30 percentage points. d.)

Market shares rose by 23 percentage points. e.)

There was a 15% increase in market shares. f.)

Market shares rose by 15 percentage points.

Answer Rationale Percentage points is the absolute increase or decrease. Market shares rose from 50 percent to 65 percent, so the absolute increase can be found with the new value minus the old value: The percentage increase is the percent change. This can be found by finding the absolute difference divided by the initial value of 50 percent: A department store manager noted that the sales of furniture contributed 20% of the store's profits in the year 2015 and 29% in the year 2016.

Of the following choices, which two statements about furniture sales are true? a.)

Furniture sales rose by 45 percentage points. b.)

There was a 31% increase in furniture sales. c.)

Furniture sales rose by 31 percentage points. d.)

There was a 9% increase in furniture sales. e.)

There was a 45% increase in furniture sales. f.)

Furniture sales rose by 9 percentage points.

Answer Rationale Percentage points is the absolute increase or decrease. Furniture sales rose from 20 percent to 29 percent, so the absolute increase can be found with the new value minus the old value: The percentage increase is the percent change. This can be found by finding the absolute difference divided by the initial value of 20 percent:

A company’s market share went from 50 to 40 percent of the total market.

Of the following choices, which two statements about the company's market shares are true? a.)

Market shares dropped by 10 percentage points. b.)

Market shares dropped by 25 percentage points. c.)

There was a 25% decrease in market shares. d.)

Market shares dropped by 20 percentage points. e.)

There was a 20% decrease in market shares. f.)

There was a 10% decrease in market shares.

Answer Rationale Percentage points is the absolute increase or decrease. Market shares declined from 50 percent to 40 percent, so the absolute decrease can be found with the new value minus the old value: The percentage decrease is the percent change. This can be found by finding the absolute difference divided by the initial value of 50 percent:

im mailed a lot of his surveys to married couples. However, he included only the name of the male spouse in the mailing address. As a result, Tim has systematically excluded the opinions of female spouses from his survey. Ideally, Tim would prefer to have a 50/50 split in male and female respondents in his sample.

Based upon the above scenario, which of the following is TRUE? a.)

Tim has uncovered deliberate bias in his methods. b.)

Tim sought to promote non-response bias in his survey. c.)

Tim sought to promote participation bias in his survey. d.)

Tim has uncovered selection bias in his methods. b.)Incorrect.

It was not that women spouses didn't want to participate, but they were not selected into the survey by only including the males spouse's name. It is not that they couldn't be reached either, since their name could have been included in the address.  This is an example of the study designer, Tim, not selecting all facets of the population.

Women spouses have been excluded, so it is a selection issue.

Survey A had the question: Should people be allowed to smoke? Another survey, B, asked respondents: Since cigarettes are dangerous and have deadly side effects such as cancer, wouldn't you agree that smoking should be controlled to save the lives of many?

Which survey can be associated with deliberate bias? a.)

Neither Survey A nor Survey B b.)

Both Survey A and Survey B c.)

Only Survey B d.)

Only Survey A b.)Incorrect.

Survey B has a specific agenda, but survey A simply asks should people be allowed to smoke.  Since survey B is providing the information about the dangers of smoking and its side effects, it is deliberately pushing for a specific response. This same format is not present in A, where it simply asks should people be allowed to smoke.

A survey asked the following question: Do you agree that drinking is okay as long as you are of the legal age and that you don't get drunk?

What type of bias does this question introduce? a.) deliberate b.) response c.) selection d.) non-response  Since the study appears to want to advance a specific notion about drinking, it would be a deliberate bias.

How about members of a local professional sports team who are conducting a survey?

Which data collection method would provide biased results for the question "What is your favorite sport?" a.)

Ask people at a shopping mall. b.)

Ask people attending a concert. c.)

Ask people attending a soccer game. d.)

Ask people walking on the beach.  Recall that bias is when the data collected differs systematically from the truth. If you asked people at a soccer game what sport was their favorite when they are at a soccer game, we might expect that they systematically like soccer more than other sports A large company is interested in opening an on-site gym for the employees and would like to know what hours the employees would prefer to have the gym open.

Which data collection method would provide an unbiased sample? a.)

Posting a request for survey volunteers in the company's breakroom b.)

Asking all employees who work from 8am - 5pm c.)

Asking five random employees from each shift d.)

Emailing a questionnaire to the employees d.)Incorrect.

Emailing is a form of response bias. Their responses will most likely be different from those who decide not to voluntarily respond.  By taking a random sample and asking at each shift, this is the most likely way to get an unbiased response.

Kendra decides to go door-to-door and survey people who live near the pet shop she owns.

On Tuesday, Kendra steps out during her lunch break and finds that many people aren't home.

Of the people who are home, Kendra discovers that most of them are elderly or stay-at-home parents.

Discovering that many people are not available to participate in her survey is an example of ______ bias. a.) deliberate b.) nonresponse c.) response d.) unintentional c.)Incorrect.

The situation described people being excluded since they are unaware of the study because they are not home, not due to their responses.  Since most people are being excluded since they are not at home during lunch, this is an example of a nonresponse bias.

Kendra thinks it's important to know how much money her customers make, so she can decide whether to offer high-end items. Because Kendra’s shop is in a small town, most of her customers are her friends and neighbors. One survey question asks, “How much money do you make each month?”

A customer who responds by writing down a really high number to impress Kendra is an example of ______ bias. a.) non-response b.) selection c.) unintentional d.) response  Since Kendra's customers come from a small town, there might be a predisposition for them to inform Kendra based on a desired outcome. This is a response bias.

Customers were asked "Why didn't you buy anything?" when they left the store without making a purchase. A few customers seem surprised by this question and many answered by saying that they forgot their wallet at home.

Customers lying about why they did not make a purchase is an example of _____ bias.

a.) deliberate b.) response c.) selection d.) non-response c.)Incorrect.

Since the study focuses on customers and they were asking them as they left the store, it is not a selection issue.  Since the bias was created from the responses of the customers, it is a response bias.

Select the example that represents self-selected sampling. a.)

Naomi goes door to door asking questions in a neighborhood that might be a good fit for the restaurant. b.)

Naomi asks the same survey question to everyone who comes to the restaurant. c.)

Naomi posts a request for survey volunteers on the restaurant's Facebook page. d.)

Naomi asks a few questions whenever she thinks a customer seems friendly.  To be self-selected, a person must volunteer to be part of the study. Here Naomi voluntarily enters the study.

Select the example that represents convenience sampling. a.)

George asks every 10th customer to fill out a survey. b.)

George asks the same survey question to the first 20 customers to visit the food truck. c.)

George hangs flyers for volunteers to answer questions for the survey on various streets and convenience stores throughout the city. d.)

George offers a free cookie to anyone who agrees to answer the survey questions. a.)Incorrect.

See above explanation - this seems to be an example of a convenience sample. Samples might have elements of other bias as well as being a convenience sample.  Since the first 20 people are asked due to the ease of asking them, this is an example of a convenience sample. We probably can assume the first 20 customers might not be like later customers.

Select the example that represents self-selected sampling. a.)

Aaron mails survey questions to all of the customers who signed up to receive offers and updates from his clothing store. b.)

Aaron walks around the mall asking questions to customers that are shopping in similar clothing stores. c.)

Aaron asks the same survey question to the 20 nearest customers in his store. d.)

Aaron asks a couple questions whenever he thinks a customer seems interested as they walk by his store.  Since those who receive the email can choose whether or not to respond, this is an example of self-selection.

Which statement about systematic errors is FALSE? a.)

They can be eliminated by repeating observations or increasing the sample size. b.)

They arise due to errors in the measuring instruments used. c.)

They are reproducible inaccuracies that are consistently in the same direction. d.)

They arise from the design of the study.  Since the error is systematic, a larger sample or repeating observations does nothing to correct it.

Which statement about systematic errors is TRUE? a.)

They can be corrected by using a larger sample size. b.)

They can be challenging to notice. c.)

They can occur when a selection bias is present. d.)

They can be eliminated if observations are repeated. a.)Incorrect.

Since the error is systematic and not random, a larger sample cannot correct it.  There can be a systematic error and selection bias that occur at the same time.

Which statement about random errors is FALSE? a.)

They arise when the sample has some different characteristics than the population. b.)

They are difficult to detect. c.)

They are less likely for small sample sizes. d.)

They do not arise from the design of the study.  As the sample gets larger, random error is less likely. With smaller samples however, random error can have a large effect.

After all of the surveys have been compiled and analyzed, the calculated level of satisfaction for “overall quality” for a sample was 6.2 ± 0.5.

Select the true statement regarding the margin of error of this scenario. a.)

The margin of error is the total number of subjects in the sample and is equal to 6.2. b.)

The margin of error is the mean value obtained from the sample and is equal to 6.2. c.)

The margin of error is the range of potential values that the true value could be and is equal to 6.2 ± 0.5. d.)

The margin of error is the amount by which the sample mean is different from the true mean and is equal to ± 0.5.  This is simply the definition of the margin of error, which in this case is the 0.5 that must be added and subtracted from the estimate to give us a confidence interval. ter all of the surveys have been compiled and analyzed, the calculated level of satisfaction for “customer service” for a sample was 7.2 ± 0.9.

Select the true statement regarding the confidence interval of this scenario. a.)

The confidence interval is the total number of subjects in the sample and is equal to 7.2. b.)

The confidence interval is the amount by which the sample mean is different from the true mean and is equal to ± 0.9. c.)

The confidence interval is the range of potential values that the true value could be and is equal to 7.2 ± 0.9. d.)

The confidence interval is the mean value obtained from the sample and is equal to 7.2. b.)Incorrect.

This refers to the margin of error and not the confidence interval. The confidence interval is the combination of the estimate +/- the margin of error.  This is simply the definition of the confidence interval. We can note that the interval runs from 6.3 to 8.1 when we add and subtract 0.9 from 7.2.

Incorrect Go to the Next Question After all of the surveys have been compiled and analyzed, the calculated level of satisfaction for “handset selection” for a sample was 6.5 ± 0.3.

Select the true statement for this scenario. a.)

The margin of error is equal to ± 0.3 and the confidence interval is equal to 6.5. b.)

The estimate is equal to 6.5 and the margin of error is equal to ± 0.3. c.)

The margin of error is equal to 6.5 and the estimate is equal to ± 0.3. d.)

The estimate is equal to 6.5 and the confidence interval is equal to ± 0.3.

 The mean value of the sample is the estimate, which is 6.5. The amount by which we expect the sample value to deviate from the true value is the 0.3.