SOLUTION: Machine A produces 3% defectives, machine B produces 5% defectives, and machine C produces 10% defectives. Of the total output from these machines, 70% of the items are from machin

Algebra ->  Probability-and-statistics -> SOLUTION: Machine A produces 3% defectives, machine B produces 5% defectives, and machine C produces 10% defectives. Of the total output from these machines, 70% of the items are from machin      Log On


   



Question 905874: Machine A produces 3% defectives, machine B produces 5% defectives, and machine C produces 10% defectives. Of the total output from these machines, 70% of the items are from machine A, 20% from B, and 10% from C. One item is selected at random from a day’s production. If inspection finds the item to be defective, what is the revised probability that the item came from machine B?
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
p(def) = .03*.70 + .05*.20 + .10*.10 = .021 + .010 + .01 = .041
P(A|B) = P(A and B)/P(B)
P(B|def) = .05*.20/.041 = .01/.041