1. The problem statement, all variables and given/known data A random variable X has the generating function f(z) = 1 / (2-z)^2 Find E(X) and Var(X). 2. Relevant equations 3. The attempt at a solution Would anyone explain in simpler terms the notion of the generating function, such that I may be able to solve problems? All I have found were proofs, but nothing of practical use. Thank you very much!