A simple random sample of size n is drawn from a population that is normally distributed. The sample mean. x. is found to be 114. and the sample standard deviation. s. is found to be 8 (a) Construct a 95% confidence interval about u if the sample size, n, Is 21. (b) Construct a 95% confidence interval about u if the sample size, n, Is 12 (c) Construct a 90% confidence interval about u if the sample size, n, is 21. d) Should the confidence intervals in parts (a)-(c) have been computed if the population had not been normally distributed