The annual rainfall in Cleveland, Ohio is approximately a normal random variable with mean $40.2$ inches and standard deviation $8.4$ inches. What is the probability that
(a) next year's rainfall will exceed 44 inches;
(b) the yearly rainfalls in exactly three of the next seven years will exceed 44 inches?
Assume that if $A_{i}$ is the event that the rainfall exceeds 44 inches in year $i$ (from now), then the events $A_{i}, i \geq 1$, are independent.