Use the sampling distribution of means to find the probabilities. The mean of the sampling distribution is the same as the mean of the population (i.e., 30,000). The standard deviation of the sampling distribution is 15,000/√30 = 2,738.61. Use NDAREA to find the probabilities:

(a). P(X=25,000) = 0
(b). P(X>25,000) = 0.966
(c). P(20,000<X<30,000) = 0.5
(d). P(X>35,000) = 0.034