The expected value of a random variable <em>X</em>, often denoted as E(<em>X</em>), indicates the probability-weighted average of all possible values/events. The general formula of expected value is
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Therefore, the expected value of the winnings from a game is
S + g = 425 g = s + 25 ----------------- We will use the method of substitution: s + s + 25 = 425 2 s = 425 - 25 2 s = 400 s = 400 : 2 s = $425 g = 200 + 25 g = $225 Answer: Seiji earned $200 and Gavin earned $225.