a. A statistics practitioner took a random sample of 50

a. A statistics practitioner took a random sample of 50 observations from a population with a standard deviation of 25 and computed the sample mean to be 100. Estimate the population mean with 90% confidence.,b. Repeat part (a) using a 95% confidence level.,c. Repeat part (a) using a 99% confidence level.,d. Describe the effect on the confidence interval estimate of increasing the confidence level.