18.For planning purposes, truss manufacturers must try to predict the number of hurricanes that will hit the eastern seaboard of the United States in any given year. If this area is hit with an average of 6 hurricanes per year, find the probability that in a given year...

a) ...fewer than 3 hurricanes will hit this area.

b) ...between 6 and 8 hurricanes (inclusive) will hit this area.

c) What is the standard deviation of this distribution?