is about measure of central tendency random variable expected value Alejandra Gonzalez-Beltran Orlaith Burke Philippe Rocca-Serra first moment http://en.wikipedia.org/wiki/Expected_value mean the expected value (or expectation, mathematical expectation, EV, mean, or the first moment) of a random variable is a data item which corresponds to the weighted average of all possible values that this random variable can take on. The weights used in computing this average correspond to the probabilities in case of a discrete random variable, or densities in case of a continuous random variable. From a rigorous theoretical standpoint, the expected value is the integral of the random variable with respect to its probability measure. μ ready for release