Suppose scores on exams in statistics are normally distributed with an unknown population mean and population standard deviation of three points. A random sample of 38 scores are taken and gives a sample mean of 63.

(a) Find and interpret a 92% confidence interval for the population mean of stats exam scores.

(b) Find and interpret an 88% confidence interval for the population mean of stats exam scores.

(c) Which interval is more accurate to estimate the true mean and which interval is wider?