Travel and Transportation. Because of forced spending cuts in Spring 2013, the Federal Aviation Administration identified 149 air traffic control towers that would be closed. In a group of 20 air traffic control towers in the Midwest, five will be closed. Suppose 6 of the 20 air traffic control towers are selected at random.
(a) What is the probability (±0.0001) that none of the 6 air traffic control towers will be closed?
P(X=0) =
(b) What is the probability (±0.0001) that at most two of the air traffic control towers will be closed?
P(X⩽2) =
(c) What is the probability (±0.0001) that at least four will be closed?
P(X⩾4) =
