记事件A:“被诊断患有肝癌”,
事件B:“确实患有肝癌”,
已知P(B)=4/10000=0.0004,
P(A|B)=0.95,P(A|Bˉ)=0.1.
(1).P(A)=P(B)P(A|B)+P(Bˉ)P(A|Bˉ)
=0.0004*0.95+0.9996*0.1=0.10034.
(2).P(B|A)=P(B)P(A|B)/P(A)
=0.0004*0.95/0.10034=0.003787.
记事件A:“被诊断患有肝癌”,
事件B:“确实患有肝癌”,
已知P(B)=4/10000=0.0004,
P(A|B)=0.95,P(A|Bˉ)=0.1.
(1).P(A)=P(B)P(A|B)+P(Bˉ)P(A|Bˉ)
=0.0004*0.95+0.9996*0.1=0.10034.
(2).P(B|A)=P(B)P(A|B)/P(A)
=0.0004*0.95/0.10034=0.003787.