The production manager of a particular jet engine component at Williams Internationalwants to find the proportion of components that have a defect in order to adjust the currentproduction model to minimize defect rate. A random sample of 120 components resulted in 7 components having a defect.

a. Calculate a 99% confidence interval for the proportion of components that have a defect.

b. Interpret the interval in part a.

c. How large of a sample would need to be taken to estimate the true proportion of components that have a defect within 3% with 99% confidence?