Question: A parachute assembly and packing plant produces thousands of parachutes each month. One month, 1200 are inspected and it is found that 0.2% have a defect.
(a) Find an estimate with a 99% confidence interval of the proportion of parachutes produced in a month that are defective.
(b) Redo (a), except with a 95% confidence level.
(c) Redo (a), with a 90% confidence level.
(d) Suppose only 800 parachutes are inspected instead of 1200, and it is still found that 0.2% are defective. Now determine an estimate with a 95% confidence interval of the proportion of parachutes produced in a month that are defective. How has decreasing the size of the sample affected the confidence interval(CI)?