My answers for b and c are incorrect . I am stuck

An electronics manufacturing process has a scheduled mean completion time of 70 minutes. It is claimed that, under new management, the mean completion time, J, is less than 70 minutes. To test this claim, a random sample of 22 completion times under new management was taken. The sample had a mean completion time of 69 minutes and a standard deviation of 8 minutes. Assume that the population of completion times under new management is normally distributed. At the 0.05 level of significance, can it be concluded that the mean completion time, J, under new management is less than the scheduled mean? OO Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places and round your answers as specified in the table. (If necessary, consult a list of EO formulas.) D (a) State the null hypothesis Ho and the alternative hypothesis H. H: H 2 70 H : H