How much does a sleeping bag cost? Let us say you want a sleeping bag that should keep you warm in temperatures from 20ºF to 45ºF. A random sample of prices ($) for sleeping bags in this temperature range was taken from a magazine.

Question

How much does a sleeping bag cost?  Let us say you want a sleeping bag that should keep you warm in temperatures from 20ºF to 45ºF.  A random sample of prices ($) for sleeping bags in this temperature range was taken from a magazine. 
93	106	86	109	81	111	118	117	118	116
For these sample data, the mean is   and the sample standard deviation is   Using the given data as representative of the population of prices of all summer sleeping bags, find a 95% confidence interval for the mean price   of all summer sleeping bags.  Round your answer to two decimal places.

81.02 to 106.78 
        95.57 to 106.78 
        92.62 to 115.43 
        95.57 to 115.43 
        92.62 to 106.78

PsyDAG · Answer

You need to calculate the mean and standard deviation first, or at least put it down in your post.

95% interval = mean ± 1.96 SD

Z = ±1.96 = (score - mean)/SD

Insert the values of mean and SD to find the score.