Surgical complications: A medical researcher wants to construct a 90% confidence interval for the proportion of knee replacement surgeries that result in complications. Part: 0 / 2 Part 1 of 2 (a) An article in a medical journal suggested that approximately 10% 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 operations is needed to obtain a 90% confidence interval with a X 5 margin of error of 0.04 using the estimate 0.1 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 90% confidence interval with a X margin of error of 0.04 when no estimate of p is available