On-Time Arrivals. The Air Travel Consumer Report is a monthly product of the Department of Transportation’s Office of Aviation Enforcement and Proceedings. The report is designed to assist consumers with information on the quality of services provided by the airlines. Following are the percentages of on-time arrivals for June 2013 by the 16 reporting airlines. 93.1 87.5 77.9 77.3 76.1 73.8 73.0 72.5 71.1 70.6 69.8 69.6 69.0 66.0 65.9 61.8

a. Identify the classes for grouping these data, using cutpoint grouping with classes of equal width 5 and a first lower class cutpoint of 60.

b. Identify the class midpoints of the classes found in part (a).

c. Construct frequency and relative-frequency distributions of the data based on your classes from part (a).

d. Draw a frequency histogram of the data based on your classes from part (a).

e. Round each observation to the nearest whole number, and then construct a stem-and-leaf diagram with two lines per stem.

f. Obtain the greatest integer in each observation, and then construct a stem-and-leaf diagram with two lines per stem.

g. Which of the stem-and-leaf diagrams in parts

(e) and

(f) corresponds to the frequency histogram in part (d)? Explain why.