Airline Load Factor In a recent year, Southwest Airlines had 3,131,727 aircraft seats available on all of its flights, and 2,181,604 of them were occupied by passengers.

America West had 2,091,859 seats available, and 1,448,255 of them were occupied.

The percentage of seats occupied is called the load factor, so these results show that the load factor is 69.7% (rounded) for Southwest Airlines and 69.2% (rounded) for America West. (The data are from the U.S. Department of Transportation.) Answer the following by assuming that the results are from randomly selected samples.

a. Test the claim that both airlines have the same load factor.

b. Given that 69.7% and 69.2% appear to be so obviously close, how do you explain the results from part (a)?

c. Generalize the key point of this example by completing the following statement:

“If two sample sizes are extremely large, even seemingly small differences in sample proportions . . .”