§5n重贝努里概型 P(4)=PCCC)+PCCC:)+PCCC) P(C)P(C:)PC)+P(C)P(C:)P(C:)+PC)P(C:)P(C:) =0.3×0.6×0.2+0.3×0.4×0.8+0.7×0.6×0.8 =0.468 P(4)=P(CC2C3)=P(C)P(C2)P(C3) =0.3×0.6×0.8=0.144 所以 PB)=0.332×0.2+0.468×0.6+0.144×0.9 =0.4768 合】返回主目录( ) ( ) ( ) ( ) P A2 = P C1 C2 C3 + P C1 C2 C3 + P C1 C2 C3 ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) = P C1 P C2 P C3 + P C1 P C2 P C3 + P C1 P C2 P C3 = 0.30.60.2+0.30.40.8+0.70.60.8 = 0.468 ( ) ( ) P A3 = P C1 C2 C3 ( ) ( ) ( ) = P C1 P C2 P C3 = 0.30.60.8 = 0.144 所以 P(B)= 0.3320.2+0.4680.6+0.1440.9 = 0.4768 返回主目录 §5 n重贝努里概型