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

See Examples For:

expected value

The expected value is the average statistical outcome you would expect if the same event were repeated and over again.

From MarketWatch ● Jul. 24, 2026

Baron said he thinks SpaceX valuation is heading much higher from the expected value of close to $2 trillion at the IPO.

From Barron's ● Jun. 8, 2026

He worried that knowing the expected value might unconsciously influence his analysis.

From Science Daily ● May 18, 2026

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

The expected value of a quantity is simply the average of its values weighted according to their probabilities.

From "Innumeracy: Mathematical Illiteracy and Its Consequences" by John Allen Paulos