The random variable X has mass function x = 0 p(x) = -09 5 x=1 1/2 x = 2 Provide your answers to two decimal places. (a) Find the moment generating function of X and evaluate it at the point t=4. (b) Find the second derivative of the moment generating function and evaluate it at the point t=4. (c) Use the m.g.f. to find the second moment of X.