1. Does each of the following tables represent a probability distribution? Explain why or why not. For those that represent a probability distribution, calculate the mean and variance of the variable X. Xi 6 9 (a) P(x) 0.5 0.25 0.25 Xi 1 2 3 4 (b) P(x) 0.4 0.4 0.4 0.2 (c) Xi 1 2 3 4 P(x) 0.5 0.3 0.3 -0.1 Using