A foreman for an injection-molding firm admits that on 13% of his shifts, he forgets to shut off the injection machine on his line. this causes the machine to overheat, increasing the probability that a defective molding will be produced during the early morning run from 4% to 21%. if a molding is randomly selected from the early morning run of a random day, what is the probability that it is defective?
Percentage of admitting molding and forgetting to shut off = 13% And not forget to shut off F' = 87% Defective molding D = 21% P(F & D) = 13% * 21% = 2.73% P(F ' & D) = 87% * 4% = 3.48% P(D) = sum of the both probabilities P(F & D) and P(F ' & D) = 6.21%
