概華伦与款程统外 P{X=3,Y=2}=P{X=3}P{Y=2}=0.7×0.6=0.42, P{X=3,Y=4}=P{X=3}P{Y=4}=0.7×0.4=0.28. 因此(X,Y)的联合分布律为 2 4 0.18 0.12 3 0.42 0.28 P{X = 3,Y = 2} = P{X = 3}P{Y = 2}= 0.70.6 = 0.42, P{X = 3,Y = 4} = P{X = 3}P{Y = 4}= 0.70.4= 0.28. 因此 (X,Y )的联合分布律为 Y X 2 4 1 3 0.18 0.12 0.42 0.28