§5n重贝努里概型 由全概率公式，得 P(B)=∑P4)P(E4） 而 P()=PCCC)+PCCC)+PCCC) =P(C )PC)PC)+PC)P(C2)PC)+PC)PC)P(C) =0.3×0.4×0.2+0.7×0.6×0.2+0.7×0.4×0.8 =0.332 合】返回主目录 由全概率公式，得 ( )  ( ) ( ) = = n i P B P Ai P B Ai 而 1 ( ) ( ) ( ) ( ) P A1 = 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0.40.2+0.70.60.2+0.70.40.8 = 0.332 返回主目录 §5 n重贝努里概型