After you have made your table, use it to construct a histogram of the data, choosing the height of the bar so that the area of each bar matches the relative frequency of your bin. Show all necessary calculations and use graph paper for your histogram to make sure that the vertical scale is consistent and correct.

An automobile assembly line operation has a scheduled mean completion time, μ, of 12 minutes. the standard deviation of completion times is 1.6 minutes. it is claimed that, under new management, the mean completion time has decreased. to test this claim, a random sample of 33 completion times under new management was taken. the sample had a mean of 11.2 minutes. assume that the population is normally distributed. can we support, at the 0.05 level of significance, the claim that the mean completion time has decreased under new management? assume that the standard deviation of completion times has not changed.