Standard deviation and mean

Question

The mean salary of public school teachers in the United States in 2012 was $50,547 with a standard deviation of $9,000. Assume these salaries are normally distributed. Find the percentage of public school teachers who earn less than $32,547.

1. 13.5%
2. 2.5%
3. 68%
4. 95%

Answer 1

With a mean of $50,547 and a standard deviation of $9000. $32, 547 would be two standard deviations below the mean which would be 2.5%. Answer (2) is correct.