Question

A quality control engineer wants to check whether, in accordance with specification, 90% of the products shipped are in perfect condition. To this end, he randomly selects 11 items from each large lot ready to be shipped and approves the lot only if all 11 are in perfect condition. If all 11 are not in perfect condition, then he holds the lot for a complete inspection.

Find the probabilities that he will commit the error of

a)Holding a lot for further inspection even though 90% of the lot’s items are actually in perfect condition;

b)Letting a lot pass through even though only 85% of the lot’s items are actually in perfect condition;

Answer 1