▣Expected value-Probability-weighted average(概率加权平均值) of the values associated with all possible outcomes. ▣Payoff(收益)-Value associated with a possible outcome. Generally speaking,if there are n possible outcomes having payoffs X1,X2.Xn and if the probability of each outcome are given by Pr,Pr2.Prn then the expected value is E(X)=PriX1+Pr2X2+.+PrnXn❑ Expected value-Probability-weighted average(概率加权平均值) of the values associated with all possible outcomes. ❑ Payoff (收益) -Value associated with a possible outcome. ❑ Generally speaking, if there are n possible outcomes having payoffs X1 , X2.Xn and if the probability of each outcome are given by Pr1 , Pr2 .Prn then the expected value is E(X) = Pr1 X1 + Pr2 X2 + . + Prn Xn