If an event E has several possible outcomes with
probabilities p1, p2,
p3, ..., and if for each of these
outcomes the amount that can be won is a1,
a2, a3, ... ,
respectively, then the mathematical expectation (or
expected value) of E is
EXPECTATION= a1p1
+ a2p2 + a3p3
+ ...
If there is a cost of playing a game, the cost of playing
must be subtracted from the expectation.
EXPECTATION = AMT. TO WIN(PROB. OF WINNING)
- COST OF PLAYING