Outhside Hospital in Bay Shore, New York, used to perform a stress test to study the heart muscle after a person has a heart attack. This hospital wants to reduce service time, which is the time it takes from the test being carried
out until the test results come out. Usually, the average service time is 68 hours. After making changes to the test
implementation process, a sample of 50 stress tests was selected. In this sample, the average service time is 32
hours, with a standard deviation of 9 hours. Make an interval estimate with a 95% confidence level (α=5%) for
the population mean of service time.