Travel and Transportation
For anyone planning to travel, either for vacation or on business, the pricing plans of airlines remain a guarded mystery. A study by CheapAir.com suggested that the cheapest fares are found 49 days before a flight. However, according to Travelers Today, the best prices are offered 21 days before a flight. The Washington, D.C.-toLos Angeles route was selected as a test case. A random sample of days was selected, and the best price for a one-way ticket was recorded 21 and 49 days prior to the flight.
a. Assume normality. Is there any evidence to suggest that the price of a ticket on this route differs if purchased 21 or 49 days in advance? Use a = 0.05.
b. Find bounds on the p value associated with this hypothesis test.
c. Find a 95% confidence interval for the difference in population mean cost per ticket. Does this confidence interval support your conclusion in part (a)? Why or why not?