Let X be the number of tumors in a fish living in a river. Suppose that it has the following probability mass function f(0) = 0.9 f(1) = 0.7 f(2) = 0.02 f(3) = 0.01 A random sample of size n = 30 is selected from this population. Approximate the probability that the mean number of tumours per fish is greater than 0.35.