The table shows a sample of late arrival times (in minutes) for two major airlines flying the route from New York’s Kennedy Airport to London’s Gatwick Airport.

a. Use a 95% confidence level and construct the appropriate interval estimate of the difference in average late arrival times for the two populations represented, assuming that the two population distributions have unequal standard deviations. 

b. Compare your result in part a to the result you would produce if you assume that the two population distributions have equal standard deviations.

Transcribed Image Text:

Phillips AlirTransAtlantic 42 37 36 52 136 38 37 39 42 98 133 37 52 194 150