If a raffle has a winning prize of $100 and each ticket costs $5 with a total of 500 tickets sold, which equation would calculate the expected value?
100 (StartFraction 1 Over 500 EndFraction) + (negative 5) (StartFraction 499 Over 500 EndFraction) = E (X)
95 (StartFraction 1 Over 500 EndFraction) + (negative 5) (StartFraction 499 Over 500 EndFraction) = E (X)
(100 minus 5) (StartFraction 1 Over 500 EndFraction) = E (X)
(100) (StartFraction 1 Over 500 EndFraction) = E (X)
Emily solved for a part when she should have solved for the whole. 875,000 should be the numerator of the equivalent ratio. 70 x 12,500 is 875,000. So the answer is 100 x 12,500 which is 1,250,000.
