Explore BrainMass

Estimated proportion defective, 95% confidence interval

Schadek Silkscreen Printing, Inc. purchases plastic cups on which to print logos for sporting events, proms, birthdays, and other special occasions. Zack Schadek, the owner, received a large shipment this morning. 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 defective in the population?

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

c. Zack has a an agreement with his supplier that he is to return lots that are 10% or more defective. Should he return this lot? Explain your decision.

© BrainMass Inc. brainmass.com July 21, 2018, 2:14 am ad1c9bdddf

Solution Preview

Please see the attached file.

a) Proportion of defective in the sample is
Hence estimated proportion of defective in the ...

Solution Summary

The expert estimates proportion defective with a 95% confidence interval.