Question

. A local car dealership advertises cars that get the following miles per gallon:15, 22, 36, 30, 38, 21
Find the variance. (Round your answer to the nearest hundreth.)

Answer 1

you can do it by hand by finding the mean \(\overline{x}\)and then computing
\[\frac{\sum x_1^2-6\overline{x}}{5}\] or else you can cheat
http://www.wolframalpha.com/input/?i=variance+15%2C+22%2C+36%2C+30%2C+38%2C+21

Answer 2

your formula does not look correct.