9.10 Airline Occupancy Rates High airline occupancy rates on scheduled flights are essential to corporate profitability. Suppose a scheduled flight must average at least 60% occupancy in order to be profit- able, and an examination of the occupancy rate for 120 10:00 A.M. flights from Toronto to Calgary showed a mean occupancy per flight of 58% and a standard deviation of 11%.

a. If u is the mean occupancy per flight and if the company wishes to determine whether or not this scheduled flight is unprofitable, give the alternative and the null hypotheses for the test.

b. Does the alternative hypothesis in part a imply a one- or two-tailed test? Explain.

c. Do the occupancy data for the 120 flights suggest that this scheduled flight is unprofitable? Test using a = 0.05.