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 450F. 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. 85 100 40 80 70 30 100 110 105 95 105 60 110 1209 90 60 70 (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 two 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 & of all summer sleeping bags. (Round your answers to two decimal places.) lower limit $ upper limit $