An automobile assembly line operation has a scheduled mean completion time, µ, of 12.3 minutes. The standard deviation of completion times is 1.8 minutes. It is claimed that, under new management, the...

Extracted text: An automobile assembly line operation has a scheduled mean completion time, µ, of 12.3 minutes. The standard deviation of completion times is 1.8 minutes. It is claimed that, under new management, the mean completion time has decreased. To test this claim, a random sample of 46 completion times under new management was taken. The sample had a mean of 12.2 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. Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places, and round your responses as specified below. (If necessary, consult a list of formulas.) (a) State the null hypothesis H, and the alternative hypothesis H,. p H, :U H :0 (b) Determine the type of test statistic to use. (Choose one) O=0 OSO (c) Find the value of the test statistic. (Round to three or more decimal places.) O