The expected value of a randomly decided process is found by taking all of the possible outcomes of the process, multiplying each outcome by its probability, and adding all of these numbers up.

The Nylon Calculus 101 entry for what is expected value and what that means for examinations of shot selection.

Niels Erik Jensen, An Introduction to Bernoullian Utility Theory: I. Utility Functions, The Swedish Journal of Economics, Vol. 69, No. 3 (Sep., 1967), pp. 163-183 ...

Expected value is the anticipated value for an investment at some point in the future and is an important concept for investors seeking to balance risk with reward.

This equation calculates the expected value of the second variable based on the actual value of the first variable. However, the actual value probably deviates from this expected value.