despite the outrageous incomes of some, the mean income of all aging rock stars is relatively modest: \$75000 with standard deviation of \$2000. on the scale, Chubby Checker, appears to do better than average: at most only 6.25% of aging rockers make more than he does. What is chubby Checkers income?
I dont understand how to use the standard deviation here, what i did was $\frac{6.25}{100} \times 75000 + 75000 $
can someone explain this to me thanks.