Question

How much does a sleeping bag cost? Let's say you want a sleeping bag that should keep you warm in temperatures from 20°F 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. 65 75 35 65 70 60 30 23 100 110 105 95 105 60 110 120 95 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 μ of all summer sleeping bags. (Round your answers to two decimal places.) lower limit $ upper limit $

Answer 1

	Values ( X )
	65	147.6225
	75	4.6225
	35	1776.6225
	65	147.6225
	70	51.1225
	60	294.1225
	30	2223.1225
	23	2932.2225
	100	522.1225
	110	1079.1225
	105	775.6225
	95	318.6225
	105	775.6225
	60	294.1225
	110	1079.1225
	120	1836.1225
	95	318.6225
	90	165.1225
	60	294.1225
	70	51.1225
Total	1543	15086.55

Mean

Standard deviation

Confidence Interval



Lower Limit =
Lower Limit = 66.2549
Upper Limit =
Upper Limit = 88.0451
90% Confidence interval is ( 66.25 , 88.05 )