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INT
The probability that a woman exposed to German measles will contract the disease is 0.2. if exposed to risk while pregnant, the probability is 0.1 that the child will suffer from a particular serious birth defect. Otherwise, the probability of such a defect is only 0.01. A child was born with this birth defect. What is the probability that the mother suffered from German measles while pregnant? The probability that a woman exposed to German measles will contract the disease is 0.2. if exposed to risk while pregnant, the probability is 0.1 that the child will suffer from a particular serious birth defect. Otherwise, the probability of such a defect is only 0.01. A child was born with this birth defect. What is the probability that the mother suffered from German measles while pregnant? @Mathematics
Baby has it - > chance it got it without the mum having it is 0.01 Chance the mum had it has to be 1 - 0.01 = 0.99
the answer key says the answer is .7143
The key point is that the probability of a defect is 0.1 if the mother is exposed, but not infected. If the mother is exposed her chance of getting infected is 0.2.
I still dont get what to do... It sounds like "the child has the birth defect, thus the mother must have had the disease and therefore the probability is 1"