Statistics and Probability Dictionary
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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
E(X) = Σ [ xi * P(xi) ]
where xi is the value of the random variable for outcome
i, and P(xi) is the probability that the random variable
will be equal to outcome i.