expected value

American  

noun

1. Statistics, Mathematics. mathematical expectation.

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expected value British  

noun

1. Also called: mathematical expectation.  statistics the sum or integral of all possible values of a random variable, or any given function of it, multiplied by the respective probabilities of the values of the variable. Symbol: E ( X ). E ( X ) is the mean of the distribution; E ( X–c ) = E ( X )– c where c is a constant

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Etymology

Origin of expected value

First recorded in 1945–50

Example Sentences

If they could have played the game a thousand times then deciding what to do would have been easier: Keep playing unless the banker’s offer is better than the expected value.

From The Wall Street Journal • Feb. 9, 2026

But for Dyne, Matteis believes the deal for Avidity is “highly validating,” as it corroborates the expected value of muscle-delivery technology and the attractiveness of the markets for even rare diseases like DMD.

From MarketWatch • Oct. 27, 2025

He said customers wanted to see investment and improvements to services, but also expected "value for money and to be treated fairly".

From BBC • Feb. 14, 2025

"But quantum physics says that there are always certain fluctuations. The fluctuations, i.e. the deviations from the expected value, are closely related to the temperature."

From Science Daily • Mar. 27, 2024

The expected value of being a Christian would then be 0 x ∞, and that was gibberish.

From "Zero: The Biography of a Dangerous Idea" by Charles Seife