Question

Carter 52, Reagan 69, G. Bush 64, Clinton 46, GW Bush 54, Obama 47. Mean=55.33333333 Standard Deviation=8.4787315. How many of the presidents ages fall within one standard deviation of the mean?

Answer 1

Take the mean and add the std dev. This is your max age.
Take the mean and subtract the std dev. This is your min age.

Count how many of the ages given fall between the min and the max. That's your answer! :)

Answer 2

So 4?