Hypothesis testing for single population mean.
The city manager of Tempe has received a complaint from the local union of firefighters stating they are underpaid. Not having much time, the city manager gathers records from a random sample of 20 firefighters and finds their average annual salary is $36,025 with the standard deviation of $575. If the city manager knows the average salary nationally is $38,300, which test of importance should be used? Why? Should it be one or two-tailed?