4. [-/0.3 Points] DETAILS BBUNDERSTAT12 7.2.013.FB.S. MY NOTES ASK YOUR TEACHER PRACTICE ANOTH The method of tree-ring dating gave the following years A.D. for an archaeological excavation site. Assume that the population of x values has an approximately normal distribution, 1,243 1,222 1,250 1,278 1,268 1,316 1,275 1,317 1,275 LA USE SALT (8) Use a calculator with mean and standard deviation keys to find the sample mean year x and sample standard deviation s. (Round your answers to four decimal places.) X = AD. (b) Find a 90% confidence Interval for the mean of all tree-ring dates from this archaeological site. (Round your answers to the nearest whole number) lower limit AD upper limit AD Need Help? Pass It Vitch 5. [-/0.3 Points] DETAILS BBUNDERSTAT12 7.2.014.MIS. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER How much does a sleeping bag cost? Let's say you want a sleeping bag that should keep you warm in temperatures from 20OF 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. BO 100 115 80 105 120 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 - $ (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 a of all summer sleeping bags. (Round your answers to two decimal places,) lower limit upper limit Need Help? Read1 Master It MacBook Air