5. The random variable X represents the number of cherries in a cherry puff, and has the probability distribution f(4) = 0.2, f(5) = 0.4, f(6) = 0.3, f(7) = 0.1, where f(x) is the probability that there are x cherries in the cherry puff. Find the probability that the average number of cherries in 36 cherry puffs is less than 5.5.