The random sample shown below was selected from a normal distribution. 9, 5, 4, 5, 7, 6 Complete parts a and b. a. Construct a 99% confidence interval for the population mean . 3.06, 8.94) (Round to two decimal places as needed.) b. Assume that sample mean x and sample standard deviation s remain exactly the same as those you just calculated but that are based on a sample of n = 25 observations. Repeat part a. What is the effect of increasing the sample size on the width of the confidence intervals? The confidence interval is as needed.) (Round to two decimal places