How much does a sleeping bag cost? Let's say you want a sleeping bag that should keep you warm in temperatures from 20F to 45 F. A random sample of prices ($) for sleeping bags in this temperature range is given below. Assume that the population of x values has an approximately normal distribution. 85 75 60 40 55 70 30 23 100 110 105 95 105 60 110 120 95 90 60 70 LA USE SALT (a) Use a calculator with mean and sample standard deviation keys to find the sample mean price x and sample standard deviation s. (Round your answers to four decimal places.) x = $ S $ (b) Using the given data as representative of the population of prices of all summer sleeping bags, find a 90% confidence interval for the mean price u of all summer sleeping bags. (Round your answers to two decimal places.) lower limit upper limit $