You are working for a VCR manufacturer. There are three shifts in the plant: morning shift, evening shift, and midnight shift. The manager suspects that the midnight shift’s productivity is lower than 70 units. He wants to shut down the midnight shift without causing any labor-management tension. That means he will take that action only when he has enough evidence. Your responsibility is to test whether the productivity of the midnight shift is really lower than 70 units. You obtain the production for 100 nights and compute the mean as 68 and the standard deviation as 15. Test at a 5 % significance level. Propose your suggestion to the manager.