Before changes to its management staff, an automobile assembly line operation had a scheduled mean completion time of 13.4 minutes. The standard deviation
of completion times was 1.4 minutes. An analyst at the company suspects that, under new management, the mean completion time, μ, is now less than 13.4
minutes. To test this claim, a random sample of 43 completion times under new management was taken by the analyst. The sample had a mean of 13.2
minutes. Assume that the population is normally distributed. Can we support, at the 0.05 level of significance, the claim that the population mean completion
time under new management is less than 13.4 minutes? Assume that the population standard deviation of completion times has not changed under new
management.
Perform a one-tailed test. Then complete the parts below.