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Math 2311 EMCF Homework 8
Sections 6.1-6.3
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1. A marketing company offers to pay $25 to the first 100 persons who respond to their advertisement and
complete a questionnaire regarding displays of their client’s product. This situation is an example of a
a.
b.
c.
d.
Simple random sample
Convenience sample
Voluntary response sample
Multistage sample
2. A SRS was selected of large urban school districts throughout New England. The selected districts
were identified as target districts. Within each district, a SRS of its high schools was chosen and the
principals of those high schools were interviewed. This situation is an example of a
a.
b.
c.
d.
Simple random sample
Convenience sample
Voluntary response sample
Multistage sample
3. Refer to question 2. Could the results of these interviews be used to infer responses of the population
of high school principals in New England?
a. Yes
b. No
Use this information for questions 4 and 5: In order to assess the membership’s attitudes about a new
Supreme Court decision, a local bar association selects a SRS of 100 lawyers from its membership list. Surveys
are delivered to the selected lawyers. 63 of the lawyers return their surveys. 43 of the respondents disagree
with the new ruling.
4. Which of the following is of great concern in this situation?
a.
b.
c.
d.
e.
Nothing is known about the parameters of the population of interest.
Nothing is stated about the methodology of the SRS.
There may be a problem with the sampling frame.
There may be a problem with non-response bias.
None of these is true.
5. Which of the following statements is true?
a.
b.
c.
d.
e.
The sample is the membership of the bar association.
The sample is the 100 selected lawyers.
The sample is the 63 respondents.
The sample is the 43 who disagree with the new ruling.
None of these is true.
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6. Voluntary response samples often under represent people with strong opinions.
a. True
b. False
7. Convenience samples often lead to under coverage bias.
a. True
b. False
8. Questionnaires with non-neutral wording are likely to have response bias.
a. True
b. False
9. In an observational study we impose a treatment on the subjects.
a. True
b. False
10. The entire group of individuals we want information about is called the sample.
a. True
b. False
11. A study is _______________ if it systematically favors certain outcomes.
a.
b.
c.
d.
e.
Biased
Confounding
Simple
Convenient
None of these
12. Which of the following describes a simple random sample (SRS)?
a.
b.
c.
d.
e.
successively smaller groups are selected within the population in stages
choosing the individuals easiest to reach
selecting one random value then choosing a cluster of subjects around it
every possible sample of a given size has the same chance to be selected
none of these
Use the following information to answer questions 13-15: A personnel director at a large company studied
the eating habits of employees by watching the movements of a selected group of employees at lunchtime.
The purpose of the study was to determine the proportion of employees who buy lunch in the cafeteria, bring
their own lunches, or go out to lunch.
13. The study could best be categorized as:
a.
b.
c.
d.
e.
a census
a survey sample
an observational study
a designed experiment
none of these
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14. If the director includes only the employees in one department in her study, she is performing a
a.
b.
c.
d.
e.
simple random sample
quota sample
convenience sample
multi-stage sample
census
15. If the director selects 50 employees at random from throughout the company and categorizes their
lunchtime practices by gender, she is:
a.
b.
c.
d.
e.
blocking for gender
testing for a lurking variable
promoting sexual harassment
testing for bias
none of these
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