A man who moves to a new city sees that there are two routes he could take to work. He drives each route for twenty days. Route A takes an average of 40 minutes, with a standard deviation of 3 minutes, and Route B will take an average of 43 minutes with a standard deviation of 2 minutes. Does route A average faster than Route B? Find a 95% confidence interval for the difference in average commuting time for the two routes. Degrees of freedom is 33