Previous Next First Last Back Forward 19P(C|A) = P(A|C)P(C) P(A|C)P(C) + P(A|C¯)P(C¯) = 0.95 × 0.005 0.95 × 0.005 + 0.05 × 0.995 = 0.087 = 8.7% 这说明用该试剂进行普查, 准确性只有 8.7%. P(A) = P(A|C)P(C) + P(A|C¯)P(C¯) Previous Next First Last Back Forward 19