Think Better · 45 sec
Expected value
A compact thinking tool for spotting patterns and avoiding mistakes.
The useful idea
- The useful idea
In probability theory, the expected value (also called expectation, mean, or first moment) is a generalization of the weighted average.
- How it works
Provided that it is finite, the expected value can be interpreted as the long-run average of results from independent repetitions of the same random experiment, as formalized by the law of large numbers.
- Why it matters
For a random variable that takes finitely many values, the expected value is the weighted average of those values, with their probabilities as weights.
Why this matters
Use Expected value as a quick check before trusting your first conclusion.
Try this
Use Expected value as a quick check before trusting your first conclusion.
Test your recall
Which idea belongs to the explanation of Expected value?
- The useful idea — correct
- How it works
- Why it matters
In probability theory, the expected value (also called expectation, mean, or first moment) is a generalization of the weighted average.