You look at a carnival game. The person running it says, "Just reach your hand into this bag. There are 9 yellow balls and 1 red ball in the bag. You get 4 chances to pull out the red ball. (You have to put the ball you drew back before you draw another ball.) You only have to pay one dollar to play, and you get 3 dollars if you pull out the red ball!"

Assuming the person running the game is telling the truth, and the balls only differ in color, would you expect to make a net profit or a net loss on this game?

(In reply to An Ambiguity by RoyCook)

An expected value, in statistics, is what happens on average.   It does not have to be able ever to occur to be able to be considered the expected value (a 7.23 as the expected value for cards valued in blackjack [aces as one, no lack of replacement considered.])

Posted by Mike Graham on 2004-12-11 21:57:58