Variability of a Discrete Random Variable
The equation for computing the variance of a discrete random variable is shown below.
σ2 = Σ { [ xi - E(x) ]2 * P(xi) }
where xi is the value of the random variable for outcome i, P(xi) is the probability that the random variable will be outcome i, E(x) is the expected value of the discrete random variable x.
let value of E(x) be a and P(xi) be P
