4. The following data set represents the average number of minutes played for a random sample of professional basketball players in a recent season. The sample is from a normally distributed population: 35.9 33.8 34.7 31.5 33.2 29.1 30.7 31.2 36.1 34.9 (a & b, 3 points each) a) What is the point estimate of the population mean? b) What is the point estimate of the population standard deviation? c) Find the 98% confidence interval of the mean time for all professional players. (6 points) d Find the 80% confidence interval of the time for all professional players. (6 points) e) Compare these two confidence intervals. Can you make a conclusion about the width of the intervals and confidence levels? Explain. (4 points)