Fresh numbers from the U.S. Department of Transportation suggest that fewer flights in the United States arrive on time than before. The explanations offered for the lackluster performance are understaffed airlines, a high volume of travelers, and overtaxed air traffic control. A transportation analyst is interested in comparing the performance at two major international airports, namely Kennedy International (JFK) in New York and O’Hare International in Chicago. She finds that 70% of the flights were on time at JFK compared with 63% at O’Hare. Suppose these proportions were based on 200 flights at each of these two airports. The analyst believes that the proportion of on-time flights at JFK is more than 5 percentage points higher than that of O’Hare.

a. Develop the competing hypotheses to test the transportation analyst’s belief.

b. Calculate the value of the test statistic and the p-value.

c. At the 5% significance level, do the data support the transportation analyst’s belief? Explain.