Question 1

An overnight opinion poll calls randomly selected telephone numbers. This polling method misses all people without a phone. Which of the following types of errors is present in this situation?

Accepted Answer

A)  processing 
B)  Nonsampling 
C)  sampling 
D)  nonresponse

Question 2

To obtain faculty opinions on a particular issue, the chief academic officer started with the five schools making up the university. Within each school, she randomly selected two departments. Once the departments were selected, seven faculty members in those departments were selected at random (or all if there were fewer than seven) to be interviewed. This is an example of:

Accepted Answer

A)  simple random sampling. 
B)  cluster sampling. 
C)  stratified random sampling. 
D)  sampling in stages.

Question 3

In order to gauge student opinion on his grading procedures, the professor divides the class into two groups: undergraduate students and graduate students. He then takes random samples from each group. This is an example of:

Accepted Answer

A)  simple random sampling. 
B)  cluster sampling. 
C)  stratified random sampling. 
D)  sampling in stages.

Question 4

Some common sources of nonsampling error in samples of human populations are

Accepted Answer

A)  using voluntary response samples; some subjects lie. 
B)  some subjects lie; some subjects can't be contacted. 
C)  some subjects can't be contacted; drawing a sample from names in a telephone directory. 
D)  Both B and C are correct. 
E)  Answers A, B, and C are correct.

Question 5

A simple random sample is

Accepted Answer

A)  any sample selected by using chance. 
B)  any sample that gives every individual the same chance to be selected. 
C)  a sample that gives every possible sample of the same size the same chance to be selected. 
D)  a sample that selects equal numbers of individuals from each stratum. 
E)  a sample that contains the same percent of each subgroup in the population.

Question 6

To study the security protocols at a major airport, ten passengers were randomly selected from each flight leaving the airport on a particular day and questioned about the security efforts they experienced while at the airport. This is an example of

Accepted Answer

A)  simple random sampling. 
B)  stratified sampling. 
C)  cluster sampling. 
D)  sampling in stages.

Question 7

Increasing the size of a probability sample

Accepted Answer

A)  decreases the level of confidence. 
B)  increases the variability of a sample statistic. 
C)  decreases the variability of a sample statistic. 
D)  increases the variability in a population parameter. 
E)  decreases the variability in a population parameter.

Question 8

Professor Lilli Gans wishes to study the relationship between a person's zodiac sign and his or her political opinions. She obtains the birthdays of all 816 students enrolled in her Astrology 101 course. Then she uses a random digits table to choose 10 students from each of the twelve zodiac signs. For example, students born from March 21 until April 19 have the Aries zodiac sign, and Professor Gans chooses 10 Aries students at random. She uses a different part of the table of random digits to choose students having each sign. After obtaining her sample, Professor Gans has the selected students fill out a questionnaire.
Professor Gans has obtained a

Accepted Answer

A)  simple random sample from her class. 
B)  systematic random sample from her class. 
C)  stratified random sample, where the strata are students with different political opinions. 
D)  stratified random sample, where the strata are students with different zodiac signs.

Question 9

A survey was sent to a simple random sample of college sophomores. The sample size was 200. When asked whether or not they liked Frank Sinatra's music, 40 of these students did not give any answer. This is an example of

Accepted Answer

A)  a stratified sample. 
B)  a census. 
C)  bias. 
D)  the margin of error. 
E)  nonresponse.

Question 10

Concerned about the sanitation training practices of its employees, a major fast-food restaurant chain randomly selected 40 of its restaurants nationwide. All employees at these 40 restaurants were tested for their knowledge of both the restaurant chain and local health code practices. This is an example of:

Accepted Answer

A)  simple random sampling. 
B)  stratified sampling. 
C)  cluster sampling. 
D)  sampling in stages.

Question 11

Some common sources of nonsampling error in samples of human populations are

Accepted Answer

A)  voluntary response samples; can't contact some subjects. 
B)  can't contact some subjects; some subjects refuse to answer. 
C)  some subjects refuse to answer; using telephone directory as the sample frame. 
D)  Answers A, B, and C are correct. 
E)  None of the above

Question 12

A Gallup Poll contacts people by dialing telephone numbers at random. A possible source of nonsampling error in this poll is that

Accepted Answer

A)  some people chosen for the sample refused to answer questions. 
B)  people without telephones could not be in the sample. 
C)  some people never answered the phone in several calls. 
D)  Both A and C are correct. 
E)  Answers A, B, and C are correct.

Question 13

Among the following, which is not a question one needs to ask before believing a poll?

Accepted Answer

A)  Who carried out the survey? 
B)  How was the sample selected? 
C)  Was the study ever conducted before? 
D)  What were the exact questions asked?

Question 14

One source of error in pre-election polls is that some people in the sample do not tell the truth about who they will vote for. This is an example of

Accepted Answer

A)  a nonsampling error. 
B)  a random sampling error. 
C)  a sampling error, but not a random sampling error. 
D)  incorrect randomization.

Question 15

A poll about the effects of marijuana legalization questioned 1025 Denver residents and 472 Colorado citizens from outside Denver. The design of the sample chose separate samples from the two groups and planned to interview more Denver residents than other Coloradans. This is a:

Accepted Answer

A)  systematic random sample. 
B)  census. 
C)  stratified random sample. 
D)  simple random sample.

Question 16

Which of the following is a source of nonsampling error in a sample survey?

Accepted Answer

A)  Voluntary response sampling 
B)  Using voter registration lists as the sampling frame 
C)  Variation due to chance in choosing a sample at random 
D)  Using 95% confidence 
E)  None of the above

Exam 4: Sample Surveys in the Real World

An overnight opinion poll calls randomly selected telephone numbers. This polling method misses all people without a phone. Which of the following types of errors is present in this situation?

In order to gauge student opinion on his grading procedures, the professor divides the class into two groups: undergraduate students and graduate students. He then takes random samples from each group. This is an example of:

Some common sources of nonsampling error in samples of human populations are

A simple random sample is

To study the security protocols at a major airport, ten passengers were randomly selected from each flight leaving the airport on a particular day and questioned about the security efforts they experienced while at the airport. This is an example of

Increasing the size of a probability sample

A survey was sent to a simple random sample of college sophomores. The sample size was 200. When asked whether or not they liked Frank Sinatra's music, 40 of these students did not give any answer. This is an example of

Some common sources of nonsampling error in samples of human populations are

A Gallup Poll contacts people by dialing telephone numbers at random. A possible source of nonsampling error in this poll is that

Among the following, which is not a question one needs to ask before believing a poll?

One source of error in pre-election polls is that some people in the sample do not tell the truth about who they will vote for. This is an example of

A poll about the effects of marijuana legalization questioned 1025 Denver residents and 472 Colorado citizens from outside Denver. The design of the sample chose separate samples from the two groups and planned to interview more Denver residents than other Coloradans. This is a:

Which of the following is a source of nonsampling error in a sample survey?