[EX02-099] One measure of airline performance is about overall flight on-time rates. For January 2005, the on-time arrival rates of domestic flights at the 31 largest U.S. airports were as follows.

ATL 69.1 BWI 74.0 BOS 62.1

••• Remainder of data on Student’s Suite CD-ROM Source: U.S. Department of Transportation, Bureau of Transportation Statistics

a. Find the range and the standard deviation for the on-time arrival rates.

b. Draw lines on the stem-and-leaf diagram drawn in answering Exercise 2.73 that represent the range and standard deviation. Remember:

The standard deviation is a measure of the spread about the mean.

c. Describe the relationship among the distribution of the data, the range, and the standard deviation.

2.100 Consider these two sets of data:

Set 1 46 55 50 47 52 Set 2 30 55 65 47 53 Both sets have the same mean, 50. Compare these measures for both sets: (x  ¯ x),   x  ¯ x , SS(x), and range. Comment on the meaning of these comparisons.