Ximpledu

Expected Value

See how to find the expected value of an event.
2 examples and their solutions.

Expected Value

Formula

E(X) = x1p1 + x2p2 + x3p3 + ...
xi: Result value of an event i
xi: Probability of an event i
p1 + p2 + p3 + ... = 1

Example

A coin is tossed once.
If you get a head, you get 2 points.
If you get a tail, you lose 1 point.
Find the expected value of the points.
Solution

Example

For the given spinner,
if you spin the arrow once,
find the expected value of the points.

Solution