Mean of a Discrete Random Variable
The mean of the discrete random variable X is also called the expected value of X. Notationally, the expected value of X is denoted by E(X). Use the following formula to compute the mean of a discrete random variable.
E(X) = μx = Σ [ xi * P(xi) ]
where xi is the value of the random variable for outcome i, μx is the mean of random variable X, and P(xi) is the probability that the random variable will be outcome i.
let the value of P(xi) be denoted by P and xi by X for our calculation
