A trucking company would like to compare two different routesfor efficiency. Truckers are randomly assigned to two differentroutes. Twenty truckers following Route A report an average of 49?minutes, with a standard deviation of 5 minutes. Twenty truckersfollowing Route B report an average of 54 ?minutes, with a standarddeviation of 3 minutes. Histograms of travel times for the routesare roughly symmetric and show no outliers.
?a) Find a? 95% confidence interval for the difference in thecommuting time for the two routes.
?b) Does the result in part? (a) provide sufficient evidence toconclude that the company will save time by always driving one ofthe? routes? Explain.
?a) The? 95% confidence interval for the difference in thecommuting time for the two routes muBminusmuA is ?(
nothing ?minutes,
nothing ?minutes).
