Question

Data accumulated by NOAA shows that the average annual precipitation for St. Louis, MO is 34 inches. If 4.7% of the time, the annual precipitation is more than 40 inches, what is the standard deviation for annual precipitation in St. Louis?

Answer 1

P(X > 40) = 0.047

Or, P((X - )/ > (40 - )/) = 0.047

Or, P(Z > (40 - 34)/) = 0.047

Or, P(Z < 6/) = 0.953

Or, 6/ = 1.675

Or, = 6/1.675

Or, = 3.582