Efforts by airlines to improve on-time arrival rates are showing results. Boston.com (December 22, 2012) reports that in the first 10 months of 2012 on-time arrival rates at U.S. airports were the highest they have been since 2003; during this period 82% of flights landed within 15 minutes of their scheduled time. Are there differences among the major airlines? The following data show the number of on-time arrivals for samples of flights taken from seven major U.S. airlines (American Airlines, Continental Airlines, Delta Air Lines, JetBlue Airways, Southwest Airlines, United Airlines, and US Airways) in 2012.

a. Use the sample data to calculate the point estimate of the population proportion of on-time arrivals for each of these seven airlines.
b. Conduct a hypothesis test to determine if the population proportion of on-time flights in 2012 is equal for these seven airlines. Using a .05 level of significance, what is the p-value and what is yourconclusion?

Transcribed Image Text:

Arrivals Airlines Airlines Lines Airways Airlines Airlines Airways On-Time 83 Late American Continental Delta Air JetBlue Southwest United US 68 12 54 96 60 69 16 18 21 23 15