A simple random sample of 50 item from a population with = 6 result in a Sample mean of 32. a. Construct a 90

A simple random sample of 50 item from a population with σ = 6 result in a Sample mean of 32.

a. Construct a 90 per cent confidence interval for the population mean µ.

b. Construct a 95 per cent confidence interval for µ.

c. Construct a 99 per cent confidence interval for µ.

A survey of 750 university students found they were paying on average €108 per week in accommodation costs. Assume the population standard deviation for weekly accommodation costs is €22.

a. Construct a 90 percent confidence interval estimate of the population mean µ.

b. Construct a 95 percent confidence interval estimate of µ.

c. Construct a 99 percent confidence interval estimate of µ.

d. Discuss what happens to the width of the confidence interval as the confidence level is increased. Does this result seem reasonable? Explain.