Statistics Exam - A study was conducted of the 12-month

Statistics Exam

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. A study was conducted of the 12-month earnings per share for two categories of airline companies, with the result shown in the chart below. Based on the data, which of the following statements is correct?

Large Airlines

Small Airlines

$4.36 $1.60

6.19 –1.98

–0.42 1.03

3.73 –0.21

0.26 –1.15

6.27 4.19

0.59

1.52

1.97

4.57

0.05

A. The large airlines have a mean earnings per share of 3.40, and the small airlines have a standard deviation of 2.01.

B. The large airlines have a standard deviation of 2.88, and the small airlines have a standard deviation of 4.04.

C. The large airlines have a mean earnings per share of 3.40, and the small airlines have a mean earnings per share of 1.22.

D. The large airlines have a variance of 4.04, and the small airlines have a variance of 8.30.

 

2. Which of the following involves inferential statistics as opposed to descriptive statistics? A. The city business office reported 35 building permits for new single-family housing units.

B. A class of 50 statistics students earned an average grade of 73.5.

C. The Alcohol, Tobacco and Firearms department reported that Houston had 1,791 registered gun dealers in 1997.

D. A local cable system, using a sample of 500 subscribers, estimates that 40 percent of its subscribers watch a premium channel at least once per day.

 

3. 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 Emprical Rule require any assumptions about the frequency distribution.

 

4. Which type of plot takes quantitative data and forms classes out of it, thus turning it into qualitative data? A. Stem-and-leaf plot

B. Dot plot

C. Histogram

D. Pie chart

 

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

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

What is the mean for the data? A. 77

B. 77.5

C. 77.7

D. 88

 

6. Consider the following distribution:

Which of the following would you expect? A. There's no difference in the values of the mean, median, and mode.

B. The mean is greater than the median, and the median is greater than the mode.

C. The mean is less than the median, and the median is less than the mode.

D. The mean is greater than the mode, which in turn is greater than the median.

 

7. If there are an odd number of data values in a set, the median will be the

A. value that appears the greatest number of times.

B. average of the two end values.

C. average of all of the values divided by the number of values in the set.

D. value that appears in the center.

 

8. To answer the question, refer to the following data.

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 is the variance for the data values? A. 1.687

B. 2.844

C. 1.6

D. 2.56

 

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

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

What is the mode for the data? A. 77.5

B. 88

C. 77.7

D. 77

 

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

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

What is the standard deviation of this data sample? A. 34.79

B. 4.31

C. 243.5

D. 5.90

 

11. What is the difference between a histogram and a bar chart? A. The adjacent rectangles in a bar chart have a gap, while those for a histogram don't.

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

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

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

 

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

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

What is the median for the data? A. 88

B. 77

C. 77.5

D. 77.7

 

 

 

 

13. If a great many data values cluster to the left of a data distribution, which then tails off to the right, the distribution is referred to as A. rightward skewed.

B. uniform.

C. normal.

D. leftward skewed.

 

14. A particular sample contains 50 data values. According to Chebyshev's theorem, which of the following is the number of values you would expect to fall within 3.0 standard deviations of the mean? A. 25

B. 45

C. 5

D. 35

 

15. When obtaining data by _______ it's most important to inquire about the purposes of the original experimenter. A. collecting data observationally

B. conducting a survey

C. reading a published source

D. performing a designed experiment

 

16. To answer the question, refer to the following data.

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 is the standard deviation for the data values? A. 2.84

B. 1.44

C. 1.687

D. 2.56

 

17. In a sample with mean x = 12 and standard deviation s = 3.5, a data point at 16.8 would have what sample z-score? A. 4.8

B. We can't know the answer without knowing the population mean μ and standard deviation σ. C. 1.37

D. 1.4

 

18. Which of the following are parameters of a population? A. σ and n B. μ and x C. μ and σ 

 

 

End of exam

D. α and σ 

19. When creating a histogram, it's important to ensure that the classes of data satisfy which properties? A. They must be all the same size.

B. No requirements are made; the individual creating the graph is free to choose any classes.

C. They must be mutually exclusive and exhaustive.

D. They must include each interval on the number line.

 

20. Which of the following statements is true? A. A population is the object upon which we collect data.

B. When taking a sample from the population, the variable involved will always be qualitative.

C. In a true census, no inferential statistics can be done, because the entire population is the sample.

D. The definition of a census is the decennial census of the United States of America.