A study of hours devoted to a graduate course outside of classroom time generates a mean score of 90 with a standard deviation of 20. The mean age of the students was 31 with a standard deviation of 5 years. What is the relative dispersion of the two data sets?

A. 2.22%; 1.6%

B. 22.22%; 16.13%

C. 34.44%; 20%

D. Not calculable without additional data

Based on the empirical rules, what percent of the observations in a data set will lie beyond two standard deviations above the mean?

A. 2.5%

B. 5%

C. 68%

D. 95%

For a sample of engineers, the mean salary is $95,000 with a standard deviation of $30,000. The median value is $80,000. What is the relative shape of the distribution and coefficient of skewness?

A. Negatively skewed; -1.00

B. Negatively skewed; 1.00

C. Positively skewed; 1.50

D. Positively skewed; 3.00

Please answer questions 14-16 using the following sample data.

13 29 41 60 89

14 26 53 7 14

What is the first quartile?

A. 11.5

B. 13.75

C. 37

D. 50.75

Based on the information in the chart in #14 (above), what is the interquartile range?

A. 6

B. 39.5

C. 41

D. 44.25

Based on the information in the chart in #14 (above), what is the 90th percentile?

A. 9.9

B. 55.5

C. 86.1

D. 89

The interquartile range describes the

A. lower 50% of observations

b. lower 25% and upper 25% of observations.

c.middle 50% of observations.

d.upper 50% of observations

A survey of passengers on domestic flights revealed these miles:

Miles Flown Number of Passengers

100 up to 500 16

500 up to 900 41

900 up to 1,300 81

1,300 up to 1,700 11

1,700 up to 2,100 9

2,100 up to 2,500 6

What is the range (in miles)?

A. 2,499

B. 1,100

C. 2,400

D. 1,999

A box plot shows:

A. the mean and variance.

B. the relative symmetry of a distribution for a set of data.

C. the percentiles of a distribution.

D. the deciles of a distribution.

What statistics are needed to draw a box plot?

A. Minimum, maximum, median, first, and third quartiles

B. Median, mean, and standard deviation

C. A mean and a dispersion

D. A mean and a standard deviation