Discussion:
Q: A marketing firm wants to estimate the average amount spent by patients at the hospital pharmacy. For a sample of 100 randomly selected patients, the mean amount spent was $65.30 and the standard deviation $8.15.
(a) Find a 99% confidence interval for the mean amount spent by patients at the pharmacy. Show your calculations and/or explain the process used to obtain the interval.
(b) Interpret this confidence interval and write a sentence that explains it.