The Director of Admissions at Rutgers University is preparing a report for the New Jersey Department of Higher Education regarding the demographics for entering classes. The director wanted to estimate the age of students enrolled. The estimate must be within 1 year of the population. Assume that ages are normally distributed.
a. Determine the minimum sample size to construct a 90% confidence interval for the population mean. Assume the population standard deviation is 1.2 years.
b. Repeat (a) with a 99% confidence interval.
c. Which level of confidence requires a larger sample size? Explain.