3. Silkscreen Printing Inc. purchases plastic cups on which to print logos for sporting events and other special occasions. The owner just received a large shipment of cups. To ensure the quality of the shipment, he selected a random sample of 300 cups.He found 15 defective. [Hint: use proportion sample calculations.]

a) What is the estimated proportion defective in the population?

b) Develop a 95% confidence interval for the proportion defective.