\fYou intend to estimate a population mean with a confidence interval. You believe the population to have a normal distribution. Your sample size is 21. Find the critical value that corresponds to a confidence level of 99%. (Report answer accurate to three decimal places with appropriate rounding.) You measure 49 randomly selected textbooks' weights, and find they have a mean weight of 76 ounces. Assume the population standard deviation is 6.1 ounces. Based on this, construct a 90% confidence interval for the true population mean textbook weight. Give your answers as decimals, to two places _ .. ... 11.. If n=14, :E(x-bar)=35, and s=6, find the margin of error at a 98% confidence level :Give your answer to two decimal places. :1 If n = 28, E = 47, and s = 13, construct a confidence interval at a 99% confidence level. Assume the data came from a normally distributed population. Give your answers to three decimal places. D