find the probability
Hello. I am having problems with this prob question, thanks for your help:
The judge comes to know the result x of the test of DNA of the accused person. If guilty, the probability of x is 90%. If innocent is 5%.
Which condition on the probability of x, subject to the two events G and I has to be satisfied so that the final probability atributed by the judge to the innocence I is 100%.
the book says P(x|G)=0. Why? I can't get it. Thank you very much.
Problem 1 is that you are already told that P(x|G)=0.9
Originally Posted by 0123
Ignore that, P(I|x)+P(G|x)=1, so P(I|x)=1 implies P(G|x)=0, so
P(G|x) = P(x|G)P(G)/P(x)
P(x)=P(I)P(x|I) + P(G)P(x|G)
Now assume P(x) != 0, and that P(G) != 0, then P(G|x)=0 implies that