单选题
The probability of A is 0.4. The probability of AC is 0.6. The
probability of (B|A) is 0.5, and the probability of ( B| AC) is 0.2.
Using Bayes' formula, what is the probability of ( A|B) ?
【正确答案】
A
【答案解析】 Using the total probability rule, we can compute the P(B) :
P(B) =[P(B|A) ×P(A)] +[P(B|AC)×P(AC) ]
P(B) = [0.5×0.4] + [0.2×0.6] =0.32 Using Bayes' formula,
we can solve for P(A|B) : P(A|B) =[ P(B|A)/P(B) ] ×P(A)
=[0.5/0.321×0.4=0.625