A manufacturing company measures the number of defects in copper pipes they produce. In 15 copper pipes, they found 5 copper pipes with defects. A. Assuming a 90% confidence, determine p Z , and the two-sided confidence interval on the true proportion of copper pipes that show defects: SPS B. Using the point estimate of p obtained from part A., what sample size is needed for a 95% confidence that the error in estimating the true value of p is no more than 0.02? (round to nearest integer) C. How large must the sample be if we wish to be at least 95% confident that the error in estimating p is less than 0.02, regardless of the sample value of p? (round to nearest integer)