Four-week summer rainfall totals, in inches, in a section of the
Midwestern United States have approximately a gamma distribution
with
α = 1.9
and
β = 5.
(a)
Find the mean, in inches, and variance of the four-week rainfall
totals.
(b)
What is the probability that the four-week rainfall total
exceeds 6 inches? (Round your answer to four decimal
places.)