Expected Value Calculator
Calculate expected value, variance, and standard deviation from a probability distribution.
Outcomes
Add value-probability pairs. Probabilities should sum to 1.
Results
Sum of Probabilities
E(X) — Expected Value
E(X²)
Var(X) — Variance
σ — Standard Deviation
Formulas
E(X) = Σ x_i × p_i
Var(X) = E(X²) − [E(X)]² = Σ(x_i − μ)² × p_i
σ = √Var(X)
References: Expected value: E(X) = Σx·p(x). Variance: Var(X) = E(X²) − [E(X)]². Standard deviation: σ = √Var(X).