A plumbing company receives a shipment of plumbing pipes from a manufacturer that gurantee only 6% of their products are defective. 200 pipe sections were selected from the lot at random.
a) Find the probability that over 8% of pipes in the shipment will be defective.
b) When the shipment of pipes is inventoried, 15 are found to be defective. Construct and interpret a 90% confidence interval for the OVERALL PROPORTION of pipes that will be defective.