You are given the following random sample from a population that you believe to be approximately normally distributed. 8.60 8.70 9.00 8.97 8.72 8.74 8.96 8.78 a. What is a 95% confidence interval for the population mean value? b. What is a 82% upper confidence bound for the population mean value? c. What is a 95% lower confidence bound for the population variance