Writing Homework Help

please assist with these question.i have 4 questions to be answered: An automobile assembly line operation has a scheduled mean completion
time, , of minutes. The standard deviation of completion
times is minutes. It is claimed that, under new management, the
mean completion time has decreased. To test this claim, a random
sample of completion times under new management was taken.
The sample had a mean of minutes.
Assume that the population is normally distributed.
Can we support, at the
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 fill in the table below.