At the beginning of each football season, Team Sports, the local sporting goods store, purchases 5,000 footballs. A sample of 25 balls is selected, and they are inflated, tested, and then deflated. If more than two balls are found defective, the lot of 5,000 is returned to the manufacturer. Develop an OC curve for this sampling plan.

a. What are the probabilities of accepting lots that are 10%, 20%, and 30% defective?

b. Estimate the probability of accepting a lot that is 15% defective.

c. John Brennen, owner of Team Sports, would like the probability of accepting a lot that is 5% defective to be more than 90%. Does this appear to be the case with this sampling plan?