Votunteering: The General Social Survey asked 1307 people whether they performed any volunteer work during the past year. A total of 520 people said they did. Part: 0/3 Partlof3 (a) Find a point estimate for the population proportion of people who performed volunteer work in the past year. Round the answer to at least three decimal places. The point estimate for the proportion of people who performed volunteer work in the past year is l l. Surgical complications: A medical researcher wants to construct a 99.9% confidence interval for the proportion of knee replacement surgeries that result in complications. Part: 0/2 Part 1 of2 (a) An article in a medical journal suggested that approximately 16% 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 i ' operations is needed to obtain a 99.9% confidence interval with a margin of error of 0.04 using the estimate 0.16 forp