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Chapter 12 Test A
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1. Suppose a poll is taken to determine voter attitude about increasing the state income tax in exchange for increased
social services (including welfare). If the poll is confined primarily to the poorer neighborhoods of the state, what results
can be expected?
a. The poll would be biased against an increase in the state income tax.
b. The people interviewed would not be candid with their answers.
c. The people would refuse to speak to the interviewer.
d. The poll would be biased in favor of increased social services.
e. The responses would accurately reflect the opinion of the state’s population.
2. In a poll about creating a publicly funded healthcare program, suppose the question is asked, “Should free healthcare be
given to people who are too lazy to work and who have never paid any taxes?” Can the answers to this question be
trusted?
a. No, because the question is biased in favor of a negative answer.
b. Yes, because most people are inclined to answer truthfully in a poll.
c. Yes, because the phrasing of a question rarely affects the answer.
d. No, because the question is ambiguous.
e. Yes, if the poll is random.
3. In regard to the outcome of a poll, as the confidence level increases,
a. The more difficult it becomes to avoid atypical cases.
b. The standard deviation becomes smaller.
c. The margin of error increases.
d. The standard deviation becomes greater.
e. The margin of error decreases.
4. Suppose a poll shows Smith leading Jones by 52 percent to 48 percent for U.S. Senate. What can be said about the
results of this poll?
a. If the margin of error is ± 1 percent, then Smith is certainly ahead of Jones.
b. If the margin of error is more than ± 2 percent, then Jones might lead Smith.
c. If the sample is random, then the results of the poll are unimpeachable.
d. If the confidence level is 99 percent, then Smith is certainly ahead of Jones.
e. If the margin of error is ± 3 percent, then Jones is ahead of Smith.
5. Suppose you are the pilot of a small commercial airplane, and you want to ensure that the plane will carry the load.
What statistic would be most useful to you?
a. The mean weight of the passengers.
b. The median weight of the passengers.
c. The modal weight of the passengers.
d. The dispersion of the data representing the weight of the passengers.
e. The standard deviation of the data representing the weight of the passengers.
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6. Suppose that the costs of operating a factory that manufactures copper pipe increase by the following amounts: copper:
6%, labor: 5%, electricity: 4%, taxes: 2%, repairs and maintenance: 3%. By how much have the costs of manufacturing
the pipe increased?
a. 20%
b. 4%
c. 6%
d. Less than 2%.
e. Less than 6%.
7. The range of a set of data is:
a. The difference between the modal value and the mean value.
b. A measure of how much the data differ from the mean value.
c. The difference between the largest and smallest values.
d. A measure of how much the data differ from the median value.
e. The difference between the median value and the mean value.
8. One way that pictograms can distort a message is by:
a. Using pastel colors to create the pictogram.
b. Using fluorescent colors to create the pictogram.
c. Blurring the lines of the pictogram.
d. Ignoring the visual effect of a three dimensional image.
e. Chopping off the bottom of the pictogram.
9. If the variance of a set of data is relatively large, then:
a. The standard deviation diverges from the variance.
b. The data tend to be more spread out from the mean point.
c. The sample does not accurately represent the population.
d. The population from which the data are extracted tends to be large.
e. Most of the data fall close to the mean point.
10. Suppose, to select a sample from a population of 3000 persons, the following procedure is followed. The names of the
people are written on identical, square pieces of thin cardboard measuring one inch on a side, and these pieces of
cardboard are then tumbled in a clothes dryer (with the heat shut off). After 30 minutes, a blindfolded person reaches in
and withdraws a selected number of names. What can be said about this sample?
a. The sample is probably biased because clothes dryers are not supposed to be used in collecting samples.
b. The sample is probably biased because people with shorter names would be selected first.
c. The sample is probably biased because the names on the top of the heap would be selected first.
d. The sample is probably biased because the names toward the front of the dryer would probably be selected first.
e. The sample is almost certainly random.
Data Set 1A
Suppose that the following table represents the length of service (in years) of the employees of a business:
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Chapter 12 Test A
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Number of
Employees
Years
1 1
6 2
1 3
3 4
4 5
11. Given Data Set 1A, what is the mean length of service of the employees?
a. 3 years.
b. 2.5 years.
c. 3.2 years.
d. 4 years.
e. 3.5 years.
12. Given Data Set 1A, what is the median length of service?
a. 3 years.
b. 3.5 years.
c. 2 years.
d. 3 years.
e. 6 years.
13. Given Data Set 1A, what is the modal length of service?
a. 4 years.
b. 6 years.
c. 5 years.
d. 3 years.
e. 3.5 years.
Data Set 2A
Suppose that the ages of 8 kittens in a pet shop are as follows:
1, 2, 2, 3, 3, 4, 4, 5
14. What is the variance for Data Set 2A?
a. 1
b. 2
c. √1.5
d. 1.5
e. 2.5
15. For Data Set 2A, what is the standard deviation?
a. √2
b. 1
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c. 1.5
d. 2
e. √1.5