Question 1184914
without the overheating, the probability of a defective molding is 2%.


if the probability holds true, then 2% of the moldings are expected to be deficient on the normal runs.


on 10% of the runs, the machine is allowed to overheat, causing the probability of a defective molding to be 20%, rather an 2%.


if the probability holds true, then 20% of the moldings are expected to be deficient on those runs where the machines are allowed to overheat.


what i get rom this is:


the overall probability of defective moldings appears to be 90% at 2% and 10% at 20% = .9 * 2% + .10 * 20% = 3.8%.


assume 1000 shifts.
90% are at 2% and 10% are at 20%.
900 shifts are at 2% and 100 shifts are at 20%.
.02 * 900 = 18 defectives in the normal runs.
.20 * 100 = 20 defectives in the overheated runs.
total defectives = 38.
38 / 100 3.8%.


i think this is how you would look at this.
give it a shot.
see how you do.