Question 1147245
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Expected value:  Find the probability of getting each color marble; multiply each probability by the value of that marble (winnings, minus the $1 cost of playing); and add those products.<br>
gold marble: probability 4/36; value (-1+5) = 4
silver marble: probability 9/36; value (-1+3) = 2
black marble: probability 21/36; value -1<br>
expected value:
{{{4((4)/36)+(2)(9/36)+(-1)(21/36) = 13/36}}}