Waiting times (in hours) at a popular restaurant are believed to be approximately normally distributed with a variance of 2.25 during busy periods.
a. A sample of 20 customers revealed a mean waiting time of 1.52 hours. Construct the 95% confidence interval for the population mean.
b. Suppose that the mean of 1.52 hours had resulted from a sample of 32 customers. Find the 95% confidence interval.
c. What effect does a larger sample size have on the confidence interval?