Let D = defect.
You want:
P(A|D)
=
=
Company A produces 60%of the total output and Company B produces the rest(40%). 5% of the goods for Company A and 10% for company B are defects.
If a good is randomly selected what is the chance of it being a defect.
I have P(Defect)= P(Defect A) + P(Defect B)
If a good is known to be a defect what is the probability it was produced by Company A.
This one I am stuck on, any help would be appreciated
Small correction in red. The numerical calculation is not affected.
I will also point out that this question is easily done by first drawing a tree diagram. Made by Company A and Made by Company B are the first two branches. Defective and not defective are the next two branches.