An electronics manufacturing process has historically had a mean completion time of 75 minutes. It is claimed that, due to improvements in the process, the mean completion time, u, is now less than 75 minutes. A random sample of 9 completion times using the new process is taken. The sample has a mean completion time of 68 minutes, with a standard deviation of 8 minutes. Assume that completion times using the new process are approximately normally distributed. At the 0.05 level of significance, can it be concluded that the population mean completion time using the new process is less than 75 minutes? Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places. (If necessary, consult a list of formulas.) (a) State the null hypothesis Ho and the alternative hypothesis H. H : H (b) Determine the type of test statistic to use. 0 x S