2. When a large truckload of mangoes arrives at a packing plant, a random sample of 150 is selected and examined for
bruises, discoloration, and other defects. Suppose 15 mangoes do not meet the required standards.

(a) Estimate with 90% confidence the percent of all mangoes on the truck that fail to meet the standards.

(b) What was the margin of error associated with your estimate. Explain its meaning.

(c) Explain the meaning of “90% confidence” in the context of this application.

(d) What would be the most conservative sample size necessary to estimate the true percent of mangoes that fail to
meet standards within 3% at 90% confidence?