VastCalc
Statistics
Expected Value Calculator
Calculate the expected value (mean) of a discrete random variable from up to 6 outcome-probability pairs.

Expected Value Calculator

Calculate the expected value (weighted average) of a discrete random variable. Enter up to 6 outcomes with their probabilities to find E(X), variance, and standard deviation.

The expected value is the long-run average outcome of a random variable.

Formula: E(X) = Σ xᵢ × P(xᵢ)

Variance: Var(X) = Σ xᵢ² × P(xᵢ) - [E(X)]² = E(X²) - [E(X)]²

Requirements:

  • All probabilities must be between 0 and 1
  • Probabilities should sum to 1

Applications: Decision analysis, gambling, insurance, investments, any scenario with uncertain outcomes.

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