## Data: Description, Collection, and Sampling

## Data: Description, Collection, and Sampling

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Questions 1 to 20: Select the best answer to each question. Note that a question and its answers may be split across a page

break, so be sure that you have seen the entire question and all the answers before choosing an answer.

1. Ten students were sampled at random from a student population. Each was asked how many courses he

or she was planning on studying in the upcoming year. The following is a list of the reported data values:

1, 2, 2, 3, 4, 5, 5, 5, 5, 6

What’s the variance for the data values?

A. 1.6

B. 2.844

C. 1.687

D. 2.56

2. Your company is trying to assess the effectiveness of its management team. It collects data on every

employee’s time with the company, position, and who their direct supervisor is. Which of these pieces of

data is quantitative?

A. Time with the company

B. Position

C. No quantitative data is included in this experiment

D. Direct supervisor

3. Consumer product manufacturers commonly include customer satisfaction surveys on product warranty

cards that are sent back to the company. An outdoors company redesigned a popular camping tent, and it

wants to know whether customers like the newer version better than the older one. So, they include in their

warranty registration card a survey that askes two questions: first, whether the customer owned the older

version of the tent and, second, whether they liked the newer version better. What variable was measured

by this experiment?

A. Camping tent design technical superiority

B. Whether customers who never owned the original design like the new tent design

C. Camping tent profitability

D. Consumer satisfaction with camping tent design

4. What’s a variable?

A. A set of units

B. A subset of units

C. A prediction or hypothesis

D. A characteristic or a property of an individual experimental unit

5. A particular sample contains 50 data values. According to Chebyshev’s theorem, which of the following

is the maximum number of values you would expect to fall within 3.0 standard deviations of the mean?

A. 20

B. 35

C. 15

D. 45

6. Use the following data sample to answer the question.

4, 14, 6, 9, 21, 3, 7, 10

What’s the range of this data sample?

A. 15

B. 18

C. 6

D. 10

7. In an effort to figure out why application rates are slipping, your college decides to set up an experiment

to determine why students who are interested in the college decide to enroll or not. The college decides to

send out a questionnaire to everyone who submitted an application to the college in 2017. In this

experiment, a survey was used to collect data. What potential bias does this method raise?

A. Self-selection bias

B. Subjective bias

C. Observational bias

D. Transformational bias

8. To answer the question, refer to the following list of raw data.

63, 71, 72, 77, 77, 78, 86, 77, 88, 88

What’s the mode for the data?

A. 87.5

B. 77.5

C. 77

D. 77.7

9. To answer the question, refer to the following list of raw data.

63, 71, 72, 77, 77, 78, 86, 77, 88, 88

What’s the mean for the data?

A. 77.7

B. 77.5

C. 87.5

D. 77

10. The following dataset represents a student’s GPA over six semesters:

3.2, 2.5, 2.1, 3.7, 2.8, 2.0

What’s the student’s median GPA?

B. 2.65

C. 2.72

E. 14.55

F. 3.5

11. Ten students were sampled at random from a student population. Each was asked how many courses

he or she was planning on studying in the upcoming year. The following is a list of the reported data values:

1, 2, 2, 3, 4, 5, 5, 5, 5, 6

What’s the standard deviation for the data values?

A. 1.6

B. 1.687

C. 2.84

D. 2.56

12. Which of the following statements about interpreting standard deviation is true?

A. Chebyshev’s Rule can’t be applied unless the frequency distribution is mound-shaped and symmetric. The Empirical Rule can

be applied to any data set, regardless of the shape of its frequency distribution.

B. Neither the Empirical Rule nor Chebyshev’s Rule can be applied to data unless the frequency distribution is mound-shaped

and symmetrical.

C. The Empirical Rule can’t be applied unless the frequency distribution is mound-shaped and symmetric. Chebyshev’s Rule can

be applied to any data set, regardless of the shape of its frequency distribution.

D. Neither Chebyshev’s Rule nor the Empirical Rule require any assumptions about the frequency distribution.

13. Robotics manufacturers can design mobility features in one of several ways. Robots can have legs,

wheels, both legs and wheels, or no legs or wheels. Using a random sample of 106 robots, researchers

found that 63 had legs only, 20 had wheels only, 8 had both legs and wheels, and 15 had no legs or wheels.

What’s the relative frequency of robots with only wheels?

A. .075

B. .142

C. .189

D. .5

14. In a sample with mean of 12 and standard deviation of 3.5, a data point at 16.8 would have what

sample z-score?

A. 1.58

B. 1.4

C. 4.8

D. 1.37

15. Describe how the mean compares to the median when a distribution is skewed to the right.

A. Mean < median

B. Both mean and median = 0

C. Mean > median

D. Mean = median

16. What’s qualitative data?

A. Measurements that can’t be measured on a natural numerical scale

B. Measurements that are measured on a natural numerical scale

C. Any set of output numbers

D. A set of units

17. What’s an estimate, prediction, or generalization about a population based on information contained in a

sample called?

B. variables.

C. data

D. statistical inference

E. samples

18. What’s the difference between a histogram and a bar chart?

A. A histogram and a bar chart both reflect qualitative data.

B. The adjacent rectangles in a histogram have a gap, while those for a bar chart don’t.

C. A histogram reflects qualitative data, while the bar chart represents quantitative data.

D. The adjacent rectangles in a bar chart have a gap, while those for a histogram don’t.

19. Use the following data sample to answer the question.

4, 14, 6, 9, 21, 3, 7, 10

What’s the standard deviation of this data sample?

A. 5.90

B. 34.79

C. 4.33

D. 243.5

20. There are several ways to make a bar graph deceptive. Which of these is sometimes used to exaggerate

differences from one data value to the next?

A. Making the graph taller than it needs to be

B. A gap in the vertical axis

C. Starting the vertical axis at a point greater than zero

End of exam

D. Making the graph shorter than it needs to be