Okuzeka
Statistics vocabulary · Probability

Expected value

Meaning in statistics, with examples

nounCommon term

In statistics, expected value means: The long-run average result of a random variable if the same process were repeated many times, found by weighting each possible value by its probability.

In Turkish: beklenen değer, beklenti

How it is used

Written E(X) and read 'the expected value of X'. Used in probability exercises, insurance, games of chance and decision analysis. The expected value need not be a value that can actually occur.

Example sentences

  1. The expected value of a single roll of a fair die is 3.5.

  2. Each ticket costs 10 lira but has an expected value of only 4 lira.

Common collocations

  • calculate the expected value
  • the expected value of X
  • positive expected value
  • expected value and variance
  • random variableA variable whose value is determined by the outcome of a random process, such as the number of heads in ten coin tosses or the waiting time for a bus.
  • probabilityA number between 0 and 1 that expresses how likely an event is: 0 means it cannot happen and 1 means it is certain.
  • meanThe sum of all the values divided by the number of values; the usual 'average' that describes the centre of a set of numbers.
  • varianceThe average of the squared distances between each value and the mean; it measures spread, and its square root is the standard deviation.

More terms: Probability

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