Cost of Flying Listed below are costs (in dollars) of roundtrip flights from JFK airport in New York City to San Francisco. All flights involve one stop and a two-week stay. The airlines are US Air, Continental, Delta, United, American, Alaska, and Northwest. 30 Days in Advance: 244 260 264 264 278 318 280
1 Day in Advance: 456 614 567 943 628 1088 536

Required:
Use the sign test to test the claim that there is no difference in cost between f lights scheduled 1 day in advance and those scheduled 30 days in advance. What appears to be a wise scheduling strategy?