Expected value
Expected value: use outcomes, probabilities. Review the formula, worked example and calculation steps.
Inputs
Use the units shown—
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Formula & explanation
E[X] = Σ xᵢpᵢ
Variables & units
- Outcomes
- comma separated
- Probabilities
- comma separated
Worked example
80% chance of 0 and 20% chance of 10 gives expectation 2.
Assumptions
An expected value need not be an outcome that can occur on a single trial.
Formula version 1.0.0. JavaScript floating-point arithmetic applies. Results display up to 6 decimal places; stored values retain available precision. Use the units shown.
Practice with an example
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