statistics
posted by julie .
a random sample of 20 prices for summer sleeping bags was taken with a sample mean of $83.75 and a sample standard deviation of $29.97
a. Find a 95% confidence interval for the mean price of all summer sleeping bags.
b. what is m i.e., what is the margin of error?

a. 95% = mean ± 1.96 SEm
SEm = SD/√n
b. If you are talking about alpha error, P = .05.