Assume that the paired sample dataare simple random samples and that the difference have a distribution that is approximately normal.
Listed below are the costs (in dollars) of flights from New York (JFK) to San Francisco for US Air, Continental, Delta, United, American, Alaska, and Northwest. Use a 0.01 significance level to test the claim that flights scheduled one day in advance cost more than flights scheduled 30 days in advance. What strategy appears to be effective in saving money when flying?
Flight scheduled one day in advance 456, 614, 628, 1088, 943, 567, 536
Flight scheduled 30 days in advance 244, 260, 264, 264, 278, 318, 280
Using Excel, we perform a t-test. See the output (in sheet 4)
t-Test: Two-Sample Assuming Unequal Variances
Variable 1 Variable 2
The expert determines if flights are cheaper when scheduled earlier.