Question

A trucking company would like to compare two different routes for efficiency. Truckers are randomly assigned to two different routes. Twenty truckers following Route A report an average of 42 ​minutes, with a standard deviation of 4 minutes. Twenty truckers following Route B report an average of 47 minutes with a standard deviation of 3 minutes. Histograms of travel times for the routes are roughly symmetric and show no outliers.

​a) Find a​ 95% confidence interval for the difference in the commuting time for the two routes.

​b) Does the result in part​ (a) provide sufficient evidence to conclude that the company will save time by always driving one of the​ routes? Explain.

Answer 1