A sample of 55 night-school students' ages is obtained in order to estimate the mean age of night-school students. x = 25 years. The population variance is 22.
(a) Give a point estimate for ?. (to one decimal place)
(b) Find the 95% confidence interval for ?. (Give your answer correct to two decimal places.)
Lower Limit:
Upper Limit
(c) Find the 99% confidence interval for ?. (Give your answer correct to two decimal places.)
Lower Limit:
Upper Limit: