Exam- DATA-DESCRIPTION, COLLECTION, AND SAMPLING

Exam- DATA-DESCRIPTION, COLLECTION, AND SAMPLING
1. 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. leftward skewed.
D. normal.

2. 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. 77
B. 77.7
C. 77.5
D. 88

3. Consider the following distribution:
Which of the following would you expect?
A. The mean is less than the median, and the median is less than the mode.
B. The mean is greater than the mode, which in turn is greater than the median.
C. The mean is greater than the median, and the median is greater than the mode.
D. There's no difference in the values of the mean, median, and mode.

4. Use the following data sample to answer the question. 4, 14, 6, 9, 21, 3, 7, 10
What is the median of this data sample?
A. There's no median value.
B. 7
C. 8
D. 9.25

5. Which of the following are parameters of a population?
A. ? and x
B. ? and ?
C. ? and n
D. ? and ?

6. 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. 4.31
B. 34.79
C. 5.90
D. 243.5

7. 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. 88
B. 77
C. 77.7
D. 77.5

8. When obtaining data by _______ it's most important to inquire about the purposes of the original
experimenter.
A. collecting data observationally
B. performing a designed experiment
C. conducting a survey
D. reading a published source

9. Consider the following chart:

Which of the measures of central tendency would best represent that data?
A. Median
B. Mode
C. Mean
D. Standard deviation

10. 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. 2.56
B. 1.44
C. 2.84
D. 1.687

11. Which type of plot takes quantitative data and forms classes out of it, thus turning it into qualitative
data?
A. Pie chart
B. Dot plot
C. Stem-and-leaf plot
D. Histogram
12. 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. 35
B. 25
C. 45
D. 5

13. Use the following data sample to answer the question.
4, 14, 6, 9, 21, 3, 7, 10
What is the variance of this data sample?
A. 243.5
B. 34.79
C. 5.90
D. 4.31

14. 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.

15. Which of the following statements is true?
A. The definition of a census is the decennial census of the United States of America.
B. A population is the object upon which we collect data.
C. In a true census, no inferential statistics can be done, because the entire population is the sample.
D. When taking a sample from the population, the variable involved will always be qualitative.
End of exam
16. Use the following data sample to answer the question.
4, 14, 6, 9, 21, 3, 7, 10
What is the mean of this data sample?
A. 8
B. 9.25
C. 7
D. There's no mean value.

17. What is the difference between a histogram and a bar chart?
A. A histogram reflects qualitative data, while the bar chart represents quantitative data.
B. A histogram and a bar chart both reflect qualitative data.
C. The adjacent rectangles in a bar chart have a gap, while those for a histogram don't.
D. The adjacent rectangles in a histogram have a gap, while those for a bar chart don't.

18. Which of the following involves inferential statistics as opposed to descriptive statistics?
A. The Alcohol, Tobacco and Firearms department reported that Houston had 1,791 registered gun dealers in 1997.
B. A class of 50 statistics students earned an average grade of 73.5.
C. The city business office reported 35 building permits for new single-family housing units.
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.

19. If there are an odd number of data values in a set, the median will be the
A. average of the two end values.
B. average of all of the values divided by the number of values in the set.
C. value that appears in the center.
D. value that appears the greatest number of times.

20. When a sample is taken from a larger population, this suggests that which of the following will be used?
A. Computation of a sample mean
B. Inferential statistics
C. Independent events
D. Descriptive statistics