The head of institutional research at a university believed

The head of institutional research at a university believed that the mean age of full-time students was declining. In 1995, the mean age of a full-time student was known to be 27.4 years. After looking at the enrollment records of all 4934 full-time students in the current semester, he found that the mean age was 27.1 years, with a standard deviation of 7.3 years. He conducted a hypothesis of H0: mu = 27.4 years versus H1: mu

Solution

Answer A. He has all the data. So the sample is the population. No need for hypothesis testing.