Chapter 9.4, Problem 18E

For Exercises 7 through 27, perform each of these steps.

a. State the hypotheses and identify the claim.

b. Find the critical value(s).

c. Compute the test value.

d. Make the decision.

e. Summarize the results.

Use the traditional method of hypothesis testing unless otherwise specified.

18. Airlines On-Time Arrivals The percentages of on-time arrivals for major U.S. airlines range from 68.6 to 91.1. Two regional airlines were surveyed with the following results. At α = 0.01, is there a difference in proportions?

	Airline A	Airline B
No. of flights	300	250
No. of on-time flights	213	185