Statistics for Management and Economics Abbreviated Edition 9th Edition By Gerald Keller – Test Bank

Complete Test Bank With Answers

 

 

Sample Questions Posted Below

 

CHAPTER 5 SECTION 1: DATA COLLECTION AND SAMPLING

TRUE/FALSE

1. 2. 3. 4. 5. 6. 7. 8. 9. An observational study involves collecting data about persons or objects by recording information

about their selected characteristics of interest.

ANS: T PTS: 1 REF: SECTION 5.1

NAT: Analytic; Sampling

Self-administered surveys usually have a high response rate.

ANS: F PTS: 1 REF: SECTION 5.1

NAT: Analytic; Sampling

In designing a survey, demographic questions must be avoided.

ANS: F PTS: 1 REF: SECTION 5.1

NAT: Analytic; Sampling

The response rate of a survey is the proportion of all people who were selected but did not complete

the survey.

ANS: F PTS: 1 REF: SECTION 5.1

NAT: Analytic; Sampling

A self-selected sample is the group of individuals who were randomly selected to be in the sample,

then agreed to participate in the study.

ANS: F PTS: 1 REF: SECTION 5.1

NAT: Analytic; Sampling

Experimental data tend to be more reliable, or “stronger,” than survey data.

ANS: T PTS: 1 REF: SECTION 5.1

NAT: Analytic; Sampling

An experiment involves collecting data about persons or objects by deliberately exposing them to

some kind of change and comparing the results.

ANS: T PTS: 1 REF: SECTION 5.1

NAT: Analytic; Sampling

A question on a survey that was not answered is an example of an open-ended question.

ANS: F PTS: 1 REF: SECTION 5.1

NAT: Analytic; Sampling

A self-selected sample is one in which the individuals choose themselves to be in the sample.

ANS: T PTS: 1 REF: SECTION 5.1

NAT: Analytic; Sampling10. “Wouldn’t you agree that foreign cars are better than American cars?” is an example of a well-worded

survey question.

ANS: F PTS: 1 REF: SECTION 5.1

NAT: Analytic; Sampling

MULTIPLE CHOICE

11. 12. 13. 14. 15. Which method of data collection is involved when a researcher counts and records the number of

students wearing backpacks on campus in a given day?

a. An experiment.

b. A survey.

c. Direct observation.

d. None of these choices.

ANS: C PTS: 1 REF: SECTION 5.1

NAT: Analytic; Sampling

Which of the following statements is true regarding the design of a good survey?

a. b. c. d. The questions should be kept as short as possible.

A mixture of dichotomous, multiple-choice, and open-ended questions may be used.

Leading questions must be avoided.

All of these choices are true.

ANS: D PTS: 1 REF: SECTION 5.1

NAT: Analytic; Sampling

A marketing research firm selects a random sample of adults and asks them a list of questions

regarding their beverage preferences. What type of data collection is involved here?

a. An experiment.

b. A survey.

c. Direct observation.

d. None of these choices.

ANS: B PTS: 1 REF: SECTION 5.1

NAT: Analytic; Sampling

Which of the following must be avoided in designing a survey?

a. Dichotomous questions.

b. Leading questions.

c. Demographic questions.

d. All of these choices are true.

ANS: B PTS: 1 REF: SECTION 5.1

NAT: Analytic; Sampling

A researcher conducts a study where she divides subjects into two groups, gives each group a certain

treatment, and records their responses. What type of data collection is being used here?

a. An experiment.

b. Direct observation.

c. A survey.

d. A census.

ANS: A PTS: 1 REF: SECTION 5.116. 17. NAT: Analytic; Sampling

The personnel director at a large company studied the eating habits of the company’s employees. The

director watched and recorded whether each employee brought his/her own lunch to work, ate at the

company cafeteria, or went out to lunch. What method of data collection was used here?

a. Direct observation.

b. An experiment.

c. A survey.

d. A personal interview.

ANS: A PTS: 1 REF: SECTION 5.1

NAT: Analytic; Sampling

Which of the following data collection methods is not observational?

a. A personal interview.

b. A telephone interview.

c. A self-administered questionnaire.

d. An experiment.

ANS: D PTS: 1 REF: SECTION 5.1

NAT: Analytic; Sampling

COMPLETION

18. 19. 20. 21. 22. In a(n) ____________________ study, there is no attempt to control factors that might influence the

variable of interest.

ANS: observational

PTS: 1 REF: SECTION 5.1 NAT: Analytic; Sampling

The ____________________ rate is the proportion of people in the sample who completed the survey.

ANS: response

PTS: 1 REF: SECTION 5.1 NAT: Analytic; Sampling

In a(n) ____________________ study, individuals are randomly assigned to different treatments and

the results are compared.

ANS: experimental

PTS: 1 REF: SECTION 5.1 NAT: Analytic; Sampling

A survey is an example of a(n) ____________________ study.

ANS: observational

PTS: 1 REF: SECTION 5.1 NAT: Analytic; Sampling

Two types of interviews that are used to collect data are ____________________ interviews and

____________________ interviews.

ANS:23. 24. personal; telephone

telephone; personal

PTS: 1 REF: SECTION 5.1 NAT: Analytic; Sampling

In a self-administered survey, the individuals in the sample are typically contacted by

____________________.

ANS: mail

PTS: 1 REF: SECTION 5.1 NAT: Analytic; Sampling

Gender, occupation, and age are all examples of ____________________ variables.

ANS: demographic

PTS: 1 REF: SECTION 5.1 NAT: Analytic; Sampling

SHORT ANSWER

25. 26. 27. Describe the difference between an observational study and an experimental study.

ANS:

In an observational study, there is no attempt to control factors that might influence the variable of

interest. In an experimental study, a factor (such as regular use of fitness center) is controlled by

randomly selecting who is exposed to that factor, thereby reducing the influence of other factors on the

variable of interest.

PTS: 1 REF: SECTION 5.1 NAT: Analytic; Sampling

Briefly discuss three methods of conducting a survey of people.

ANS:

a. b. c. Personal interview: involves an interviewer soliciting information from a respondent by

asking prepared questions; it has a higher expected response rate but is typically

expensive.

Telephone interview: involves soliciting information by calling people. This is usually less

expensive, but it is also less personal and has a lower expected response rate.

Self-administered survey: this is an inexpensive method of conducting a survey which is

usually mailed to a sample of people; it usually has a very low response rate.

PTS: 1 REF: SECTION 5.1 NAT: Analytic; Sampling

Give three important points to consider when designing a questionnaire.

ANS:

Any three of the following are acceptable:

a. b. c. Keep the questionnaire as short as possible.

Design the questions to be short, simple, and clearly worded.

Consider beginning with simple demographic questions to help respondents get started

and become comfortable quickly.28. d. Consider using a combination of dichotomous questions, multiple-choice questions, and

open-ended questions.

e. Avoid using leading questions.

f. When preparing the questions, think about how you intend to tabulate and analyze the

responses.

PTS: 1 REF: SECTION 5.1 NAT: Analytic; Sampling

List one advantage and one disadvantage of a telephone interview as a method of data collection.

ANS:

29. Advantage: It is usually less expensive than other methods of data collection.

Disadvantages: It is less personal, has a lower expected response rate, and many people will refuse to

respond to telephone surveys unless the issue is of interest to them.

PTS: 1 REF: SECTION 5.1 NAT: Analytic; Sampling

List one advantage and one disadvantage of a personal interview as a method of data collection.

ANS:

30. Advantages: It has a higher expected response rate than other methods of data collection. In addition,

there will probably be fewer incorrect responses resulting from respondents misunderstanding some

questions, because the interviewer, if asked, can clarify misunderstandings.

Disadvantages: It has the potential for bias if the interviewer says too much whenever asked to clarify

misunderstandings of some questions. The main disadvantage of personal interviews is that they are

expensive, especially when travel is involved.

PTS: 1 REF: SECTION 5.1 NAT: Analytic; Sampling

Discuss one advantage and one disadvantage of a self-administered survey as a method of data

collection.

ANS:

31. Advantages: It is an inexpensive method of conducting a survey, since it is usually mailed to a sample

of people, and is therefore attractive when the number of people to be surveyed is large.

Disadvantages: Self-administered surveys usually have low response rates and may have a relatively

high number of incorrect responses due to respondents misunderstanding some questions.

PTS: 1 REF: SECTION 5.1 NAT: Analytic; Sampling

NARRBEGIN: Soft Drinks

Soft Drinks

A soft drink manufacturer has been supplying its products in bottles to grocery stores and in cans to

small convenience stores. The company is analyzing sales of this product to determine which type of

packaging is preferred by customers.

NARREND

{Soft Drink Narrative} Is this study observational or experimental? Explain.32. 33. 34. 35. ANS:

The study is observational. The statistics practitioner did not randomly assign stores to selling bottles

or cans. Type of store and type of packaging cannot be separated here.

PTS: 1 REF: SECTION 5.1 NAT: Analytic; Sampling

{Soft Drink Narrative} Outline a better method for designing this study, so the same types of stores

don’t get the same types of packaging.

ANS:

Randomly assign some grocery stores to receive bottles and the other grocery stores to receive cans.

Randomly assign some convenience stores to receive bottles and the other convenience stores to

receive cans. Or, have each store (convenience or grocery) carry both bottles and cans.

PTS: 1 REF: SECTION 5.1 NAT: Analytic; Sampling

NARRBEGIN: Smoking and Heart Attacks

Smoking and Heart Attacks

A medical researcher is interested in investigating the relationship between smoking and heart attacks

NARREND

{Smoking and Heart Attacks Narrative} Briefly describe how the researcher might design an

observational study to investigate the relationship between smoking and heart attacks

ANS:

Randomly sample a group of smokers and randomly sample a group of nonsmokers. Follow these

individuals and find the proportion of each group that has a heart attack. Or, sample a group of

individuals that had a heart attack and find out what proportion of them smoked and what proportion

did not smoke.

PTS: 1 REF: SECTION 5.1 NAT: Analytic; Sampling

{Smoking and Heart Attacks Narrative} What type of studies are plausible in this particular scenario,

observational studies or experiments?

ANS:

Observational studies are the only choice here. Experimental data would require the medical

researcher to randomly assign some people to smoke and others not to smoke. This of course is not

ethical.

PTS: 1 REF: SECTION 5.1 NAT: Analytic; Sampling

{Smoking and Heart Attacks Narrative} How can you show that smoking causes heart attacks without

being able to do a designed experiment?

ANS:

Instead of conducting one simple observational study, conduct many observational studies, each

looking at smoking and heart attacks from a different angle, for all different populations. Once the

entire body of evidence from all these studies is examined, the connection can be seen between

smoking and heart attacks.

PTS: 1 REF: SECTION 5.1 NAT: Analytic; Sampling

 

CHAPTER 5 SECTION 2-4: DATA COLLECTION AND SAMPLING

TRUE/FALSE

36. 37. 38. 39. 40. 41. 42. 43. 44. 45. A person receives a mail survey and shreds it without opening it. This causes nonresponse error.

ANS: T PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

Self-selected samples have no bias because they are chosen by the people themselves.

ANS: F PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

A cluster sample occurs when you randomly select groups, and for each group selected, you sample

every single member of that group.

ANS: T PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

The larger the sample size is, the more accurate we can expect our sample estimates to be.

ANS: T PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

Selection bias occurs when researchers select biased questions to include on a survey.

ANS: F PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

The target population is the population about which we want to draw inferences and conclusions, while

the sampled population is the actual population from which the sample has been taken.

ANS: T PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

A target population and a sampled population mean the same thing.

ANS: F PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

A self-selected sample represents the sampled population but not the target population.

ANS: T PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

A nonsampling error can be caused by the wording of a question.

ANS: T PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

When responses are not obtained from some members of the sample, bias is introduced.46. 47. 48. 49. 50. 51. 52. 53. 54. ANS: T PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

A sampling error can be reduced by taking a larger sample size.

ANS: T PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

Sampling error refers to the difference between the sample and the population that exists only because

of the observations that happened to be selected for the sample by chance.

ANS: T PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

Sampling error is the result of a mistake made during the sampling process.

ANS: F PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

Cluster samples typically cost less but they also increase sampling error.

ANS: T PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

A simple random sample is chosen in such a fashion that every possible subset of the same size has an

equal chance of being selected.

ANS: T PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

Nonresponse error occurs when responses are not obtained from some members of the sample.

ANS: T PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

Nonresponse error occurs when someone was not selected to participate in the survey.

ANS: F PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

Selection bias is a systematic tendency to favor including individuals with particular characteristics,

while excluding individuals with other characteristics.

ANS: T PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

To reduce sampling error, minimize the chance for bias to occur during sampling.

ANS: F PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

MULTIPLE CHOICE55. 56. 57. 58. 59. 60. When every possible sample with the same number of observations is equally likely to be chosen, the

result is called a:

a. simple random sample.

b. stratified random sample.

c. cluster sample.

d. biased sample.

ANS: A PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

The manager of the customer service division of a major consumer electronics company is interested

in determining whether the customers who have purchased a videocassette recorder over the past 12

months are satisfied with their products. If there are 4 different brands of videocassette recorders made

by the company, the best sampling strategy would be to use a:

a. simple random sample.

b. stratified random sample.

c. cluster sample.

d. self-selected sample.

ANS: B PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

Which of the following causes sampling error?

a. b. d. Taking a random sample from a population instead of studying the entire population.

Making a mistake in the process of collecting the data.

c. Nonresponse bias.

All of these choices are true.

ANS: A PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

A pharmaceutical company interested in measuring how often physicians prescribe a certain drug has

selected a simple random sample from each of two groups: M.D. (Medical Doctors) and D.O.

(Osteopaths). What is this type of sampling called?

a. Simple random sampling.

b. Cluster sampling.

c. Stratified random sampling.

d. None of these choices.

ANS: C PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

When the population is divided into mutually exclusive sets, and then a simple random sample is

drawn from each set, this is called:

a. simple random sampling.

b. stratified random sampling.

c. cluster sampling.

d. selection bias.

ANS: B PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

Which of the following types of samples is almost always biased?

a. Simple random samples.61. 62. 63. 64. 65. b. Stratified random samples.

c. Cluster samples.

d. Self-selected samples.

ANS: D PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

The difference between a sample mean and the population mean is called:

a. nonresponse error.

b. selection bias.

c. sampling error.

d. nonsampling error.

ANS: C PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

Which of the following types of samples should not be used to make good statistical inferences from a

sample to a population?

a. Stratified random samples.

b. Self-selected samples.

c. Cluster samples.

d. All of these choices are true.

ANS: D PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

Which of the following is an example of a nonsampling error?

a. b. c. d. Some incorrect responses are recorded.

Responses are not obtained from all members of the sample.

Some members of the target population cannot possibly be selected for the sample.

All of these choices are true.

ANS: D PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

The Admissions Officer from a large university mailed a survey to 600 students selected at random.

The sample was designed to include 150 students randomly selected from each of the freshman,

sophomore, junior, and senior classes on campus. What sampling method was used?

a. Simple random sample

b. Systematic sample

c. Stratified random sample

d. Cluster sample

ANS: C PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

Which of the following situations lends itself to cluster samples?

a. b. c. d. When it is difficult to develop a complete list of the population members.

When the population members are widely dispersed.

When selecting and collecting data from a simple random sample is too costly.

All of these choices are true.

ANS: D PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling66. 67. To give away a door prize, the hostess of a Tupperware party put each person’s name into a hat, mixed

them up, and selected one name. What sampling method was used?

a. Simple random sample

b. Systematic sample

c. Stratified random sample

d. Cluster sample

ANS: A PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

Which of the following describes selection bias?

a. b. A leading question is selected for inclusion in the survey.

Some members of the target population are excluded from possible selection for the

sample.

c. d. A person selected for the sample has a biased opinion about the survey.

All of these choices are true.

ANS: B PTS: 1 REF: SECTION 5.2-5.4

NAT: Analytic; Sampling

COMPLETION

68. 69. 70. 71. 72. 73. Proper interviewer training helps to reduce ____________________ error.

ANS: nonsampling

PTS: 1 REF: SECTION 5.2-5.4 NAT: Analytic; Sampling

Excluding some members of the target population results in ____________________ bias.

ANS: selection

PTS: 1 REF: SECTION 5.2-5.4 NAT: Analytic; Sampling

____________________ error results from the failure to collect data from all subjects in the sample.

ANS: Nonresponse

PTS: 1 REF: SECTION 5.2-5.4 NAT: Analytic; Sampling

____________________ error refers to differences between the sample and the population.

ANS: Sampling

PTS: 1 REF: SECTION 5.2-5.4 NAT: Analytic; Sampling

____________________ error is due to mistakes made in the acquisition of data.

ANS: Nonsampling

PTS: 1 REF: SECTION 5.2-5.4 NAT: Analytic; Sampling

A(n) ____________________ sample is obtained by separating the population into groups and taking

a simple random sample from each group.74. ANS:

stratified

stratified random

PTS: 1 REF: SECTION 5.2-5.4 NAT: Analytic; Sampling

____________________ sampling is particularly useful when it is difficult or costly to develop a

complete list of the population members.

ANS: Cluster

PTS: 1 REF: SECTION 5.2-5.4 NAT: Analytic; Sampling

SHORT ANSWER

75. 76. 77. 78. What is meant by a self-selected sample? Why are self-selected samples not desirable?

ANS:

A self-selected sample is a sample formed primarily on the basis of voluntary inclusion, with little

control by the designer of the survey. Self-selected samples are usually biased, because those who

participate are more interested in the issue than those who don’t, and therefore probably have a

different opinion.

PTS: 1 REF: SECTION 5.2-5.4 NAT: Analytic; Sampling

A senator wants to estimate the mean age of registered voters in her state. Unfortunately, she does not

have a complete list of households in her state. Describe a sampling plan that would be suitable for her

purposes.

ANS:

Use cluster sampling, where each city block is a cluster. Select a certain number of state counties at

random, then for each city block selected, sample each household in that county.

PTS: 1 REF: SECTION 5.2-5.4 NAT: Analytic; Sampling

The Chairman of a College of Business with five departments wants to estimate the average number of

student-hours lost per month due to illness of their professors. Describe a sampling plan that will help

the Dean compare the average student-loss hours for the five departments.

ANS:

The Chairman can take one simple random sample from each department for comparison purposes.

That means he is taking a stratified random sample, where the strata are the five departments.

PTS: 1 REF: SECTION 5.2-5.4 NAT: Analytic; Sampling

Briefly describe three types of nonsampling errors.

ANS:

a. b. Errors in data acquisition: Errors that arise from the recording of incorrect responses.

Nonresponse error: Errors that arise when responses are not obtained from some members

of the sample.c. 79. 80. 81. 82. Selection bias: Errors that arise when some members of the target population cannot

possibly be selected for the sample.

PTS: 1 REF: SECTION 5.2-5.4 NAT: Analytic; Sampling

Pollsters want to know what percentage of all registered voters in Missoula, Montana, intend to vote in

the next election. They visit with 350 people at the downtown shopping mall during one afternoon and

ask each person whether or not they intend to vote. Are the target population and the sampled

population the same in this case? Explain.

ANS:

In this situation, the target population and the sampled population are not the same. The target

population consists of all registered voters in Missoula, Montana. The sampled population, however,

consists of anyone in Missoula who was at that mall that afternoon (registered voters or not), thereby

excluding a very large portion of the Missoula, Montana, registered voters.

PTS: 1 REF: SECTION 5.2-5.4 NAT: Analytic; Sampling

Give an example of a poll that involves a self-selected sample.

ANS:

Choose any recent radio or television poll based on responses of listeners who phone in on a volunteer

basis. Another example is a survey that appears on an Internet website.

PTS: 1 REF: SECTION 5.2-5.4 NAT: Analytic; Sampling

Is it possible for a sample to yield better results than a census, from a practical standpoint? Explain.

ANS:

Yes. In any case where the population is large in size, a census will likely contain significantly more

nonsampling errors than a carefully conducted sample survey.

PTS: 1 REF: SECTION 5.2-5.4 NAT: Analytic; Sampling

A regular feature in many newspapers asks readers to respond via e-mail to a survey question. The

percentages of yes and no responses are usually reported the following day. Should we ignore the

results of these surveys? Explain.

ANS:

Yes, we should ignore the results because this is an example of a self-selected sample. Self-selected

samples are almost always biased because they tend to only represent those with strong opinions.

PTS: 1 REF: SECTION 5.2-5.4 NAT: Analytic; Sampling