A rental car company has noticed that the distribution of the number of miles customers put on rental cars per day is skewed to the right, with some occasional high outliers. The distribution has a mean of 80 miles and a standard deviation of 50 miles.

Which of the following distributions would have thesmalleststandard deviation?

(a) Number of miles put on a rental car in one day

(b) Average number of miles put on a rental car per day across 5 customers

(c) Average number of miles put on a rental car per day across 25 customers

or (d) Distributions of all of the above would have the same standard deviation.