A random sample of 40 new cars was taken with a mean dealer sticker price of $24,310. Assuming that the population standard deviation is σ = $7,200, find the confidence interval for the mean price, μ, of all dealer sticker prices of new cars: for a confidence level of 90% in thousands of dollars:
In the above problem, suppose σ was not given. You have computed the sample standard deviation to be s = $7,350. Assuming the sample size of 40 can be considered as large, compute the confidence interval for a confidence level of 90%.
(22.40, 26.24)
(22.08, 26.54)
(20.44), 28.18)