Question: Travel and Transportation During Summer 2013, American Airlines introduced a new method for passengers to board a narrowbody aircraft. The new procedure affected passengers traveling light, those carrying one item that fits under the seat. The system was designed to decrease the total boarding time, and improve on-time performance.8 Independent random samples of American and US Airways flights were obtained and the boarding time (in minutes) for each was recorded. The summary statistics are given in the following table.
Is there any evidence to suggest that the new boarding procedure has decreased the population mean boarding time? Use a = 0.05, and assume the populations are normal with equal variances.