Surgical complications: A medical researcher wants to construct a 99.5% confidence interval for the proportion of knee replacement surgeries that result in complications. Part 1 of 2 (a) An article in a medical journal suggested that approximately 6% of such operations result in complications. Using this estimate, what sample size is needed so that the confidence interval will have a margin of error of 0.04? A sample of 278 operations is needed to obtain a 99.5% confidence interval with a margin of error of 0.04 using the estimate 0.06 for P. Part: 1/2 Part 2 of 2 (b) Estimate the sample size needed if no estimate of P is available. A sample of operations is needed to obtain a 99.5% confidence interval with a margin of error of 0.04 when no estimate of P is available.