The contract between a manufacturer of electrical equipment (such as resistors or condensors) and a purchaser provides that out of each lot of 100 items 2 will be selected at random and subjected to a test. In negotiations for the contract the following two acceptance sampling plans are considered. Plan (a): reject the lot if both items tested are defective; otherwise accept the lot. Plan (b): accept the lot if both items tested are good; otherwise reject the lot. Obtain the operating characteristic curves of each of these plans. Which plan is more satisfactory to (i) the purchaser, (ii) the manufacturer? If you were the purchaser, would you consider either of the plans acceptable?