Question: A department manager at Mega Corp. is trying to determine if the amount spent on trip travel expenses by his department differs from the average amount spent by similar departments. He has access to the records of trip travel expenses for his department and he determines that the average per expenditure by his department was $2,757. He needs to determine the mean amount spent on trip travel expenses of other departments. To accomplish this, he takes a random sample of 18 trip travel expenses at a number of different departments similar to his and collects the amounts spent. His sample has a mean of $2,340 with a standard deviation of $87.

A. Based on his sample construct a 95% confidence interval for the mean amount spent by all other departments on trip travel expenses.

B. Does the amount spent on trip travel expenses by his department differ from the average amount spent by similar departments? Explain.