Question: From a sample of 12 boys the mean bodyweight was found to be 115 pounds with a sample standard deviation of 8.1 pounds. Assuming the distribution is approximately normal, answer the following questions and show all your work:

a) Calculate a 95% confidence interval for the population mean \(\mu \).

b) What is the margin of error of your confidence interval?

c) How large a sample would be needed to reduce this margin of error to three?