1. The problem statement, all variables and given/known data Let X denote a random variable with the following probability mass function: P(j)= 2^(-j), j=1,2,3,..... (a) Compute the moment generating function of X. (b) Use your answer to part (a) to compute the expectation of X. 2. Relevant equations m.g.f of X is M (t) = E[e^tX] 3. The attempt at a solution I computed the MGF (X) to be: e^t/(2-e^t). I need a suggestion about the next step. I'm confused about the relationship between the MGF and expectation of X. Thanks!