SSP Inc. purchases plastic cups on which to print logos for various corporate events. The owner, Steven Stephenson, received a large shipment this week. To ensure the quality of the shipment, he selected a random sample of 300 cups. He found 15 to be defective.

a. What is the estimated proportion that was defective in the population?

b. Develop a 97% confidence interval for the proportion that was defective.

c. Steven has an agreement with his supplier that he is to return shipments that are 10% or more defective. Should he return this shipment? Explain your decision.