Exam (elaborations)
MIND ON STATISTICS 5TH EDITION BY UTTS - TEST BANK
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- Statistics
- Institution
- Statistics
Complete Test Bank (with Questions Answers)
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, Chapter 1Mind on Statistics Test Bank
Chapter 1
Sections 1.1 – 1.3
Questions 1 to 3: Suppose you were to read about a study showing that people who sleep less than five hours a
night have twice as much risk of a premature death as people who sleep seven or eight hours a night.
1. Can you conclude that sleeping the shorter hours causes a higher risk of premature death?
A. No, because the result was clearly based on an observational study.
B. Yes, because the result was clearly based on a randomized experiment.
C. The answer depends on whether the research was based on an observational study or a randomized
experiment, and it isn't obvious which was used.
D. No, because the baseline risk of premature death is not given.
KEY: A
2. The "baseline risk" in this context is
A. the risk of premature death for people who sleep less than five hours a night.
B. the risk of premature death for people who sleep seven or eight hours a night.
C. the risk of premature death for all people.
D. the risk of premature death at the beginning of the study for those in the study.
KEY: B
3. Which of the following is not an example of a possible "confounding variable" in this study?
A. Medications a person is taking.
B. The amount of alcohol a person drinks in the evening.
C. The amount of stress a person is under in their work.
D. The amount of sleep a person gets per night.
KEY: D
Questions 4 to 6: A randomized experiment was done by randomly assigning each participant either to walk for half
an hour three times a week or to sit quietly reading a book for half an hour three times a week. At the end of a year
the change in participants' blood pressure over the year was measured, and the change was compared for the two
groups.
4. This is a randomized experiment rather than an observational study because
A. blood pressure was measured at the beginning and end of the study.
B. the two groups were compared at the end of the study.
C. the participants were randomly assigned to either walk or read, rather than choosing their own activity.
D. a random sample of participants was used.
KEY: C
5. The two treatments in this study were
A. walking for half an hour three times a week and reading a book for half an hour three times a week.
B. having blood pressure measured at the beginning of the study and having blood pressure measured at the
end of the study.
C. walking or reading a book for half an hour three times a week and having blood pressure measured.
D. walking or reading a book for half an hour three times a week and doing nothing.
KEY: A
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,Chapter 1
6. If a statistically significant difference in blood pressure change at the end of a year for the two activities was
found, then
A. it cannot be concluded that the difference in activity caused a difference in the change in blood pressure
because in the course of a year there are lots of possible confounding variables.
B. whether or not the difference was caused by the difference in activity depends on what else the participants
did during the year.
C. it cannot be concluded that the difference in activity caused a difference in the change in blood pressure
because it might be the opposite, that people with high blood pressure were more likely to read a book than
to walk.
D. it can be concluded that the difference in activity caused a difference in the change in blood pressure.
KEY: D
7. Which of the following is not a component of "Statistics" as defined in Chapter 1?
A. Procedures and principles for gathering data
B. Procedures and principles for making decisions when faced with uncertainty
C. Procedures and principles for analyzing data and information
D. Procedures and principles for turning uncertainty into certainty
KEY: D
8. Which of the following is true about a dotplot and a five-number summary?
A. A dotplot displays all of the individual responses while a five-number summary does not.
B. A five-number summary displays all of the individual responses while a dotplot does not.
C. Both a dotplot and a five-number summary display all of the individual responses.
D. Neither a dotplot nor a five-number summary displays all of the individual responses.
KEY: A
9. The five numbers in a five-number summary are the
A. lowest value, mean, median, mode, and the highest value.
B. lowest value, lower margin of error, median, upper margin of error, and the highest value.
C. lowest value, lower quartile, median, upper quartile, and the highest value.
D. lowest value, 2nd lowest value, middle value, 2nd highest value, and the highest value.
KEY: C
10. Student grade point averages (GPAs) are calculated by assigning a number to each letter grade earned, with
A = 4, B = 3, C = 2, D = 1 and F = 0, then finding the average. A student proposes using the median of the
numbers instead and calls this medGPA. A student has taken five courses (all an equal number of credit hours)
and the grades were A, A, F, B, A. The usual GPA for these grades is 3.0. Should the student prefer using the
median (medGPA)?
A. No, because medGPA is F = 0 for this student.
B. It doesn't matter, because medGPA is also B = 3.0 for this student.
C. Yes, because medGPA is A = 4.0 for this student.
D. No, because if the student takes one more course and gets an A or B, the usual GPA will go up but the
medGPA will stay the same.
KEY: C
11. A pop quiz in a class resulted in the following eight quiz scores: 0, 60, 66, 78, 82, 96, 98, 100.
The five-number summary for these test scores is
A. 0, 63, 80, 97, 100.
B. 66, 78, 82, 96, 98.
C. 0, 66, 82, 98, 100.
D. 0, 25, 50, 75, 100.
KEY: A
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12. Which of the following is true about the use of sample surveys?
A. Everyone in the population must also be in the sample.
B. Data from people in the sample are used to gain information about the population.
C. Data from people in the population are used to gain information about the sample.
D. The population is a subset of the sample.
KEY: B
13. Which of the following is true about the margin of error for the most common types of surveys?
A. If the number of individuals in the sample were to be substantially increased, the margin of error would
decrease.
B. If the number of individuals in the sample were to be substantially decreased, the margin of error would
also decrease.
C. If the number of individuals in the sample were to be substantially increased, the margin of error would not
change.
D. If the number of individuals in the sample were to be substantially decreased, the margin of error would not
change.
KEY: A
14. Suppose a Gallup Poll using a sample of 400 individuals found that 25% of them supported a particular opinion.
An interval that is 95% certain to contain the truth about the population percent who support that opinion is
A. 25% 0.05% or 24.95% to 25.05%.
B. 25% 0.25% or 24.75% to 25.25%.
C. 25% 5% or 20% to 30%.
D. 25% 20% or 5% to 45%.
KEY: C
15. If a magazine sends a survey to a random sample of 10,000 of its subscribers but only 3000 of them return the
survey, the sample results may not be representative of the population of subscribers because
A. they used a self-selected sample.
B. there is likely to be nonresponse bias.
C. a volunteer sample was used.
D. they used a random sample.
KEY: B
16. In the study described in Case Study 1.4, questionnaires were sent to 100,000 women asking about love, sex and
relationships. Only 4.5% of the women responded. This means that
A. the margin of error for the survey was 4.5%.
B. a random sample was not contacted.
C. women who felt strongly did not respond.
D. nonresponse bias was likely to be a major problem.
KEY: D
17. “Does Prayer Lower Blood Pressure” was a question asked in Case Study 1.5. The moral of the story was
A. cause-and-effect conclusions can generally be made in an observational study.
B. cause-and-effect conclusions cannot generally be made in an observational study.
C. cause-and-effect conclusions can generally be made in an experiment.
D. cause-and-effect conclusions cannot generally be made in an experiment.
KEY: B
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