1.31 Percent on-time arrivals and departures of flights during the fourth quarter of 2003 at major U.S.

airports (http://airconsumer.ost.dot.gov) are listed in Table 1.11.

a Compare the distributions of on-time arrivals and on-time departures by constructing both histograms and boxplots for each dataset.

b What proportion of airports listed in Table 1.11 meet or exceed the goal of 90% on-time departures.

c What proportion of airports listed in Table 1.11 meet or exceed the goal of 90% on-time arrivals.

d Does the empirical rule hold better for arrival or departure data? Can you give a reason for your answer?

e What percent of airports had percent arrivals within 5% of the mean?

f What percent of airports had percent departures within 5% of the mean?

g Identify those airports that can be described as outliers for on-time arrivals. Do the same for on-time departures.

h Is Atlanta better on arrivals or departures, based on comparison to the other airports?

What about Chicago O’Hare?