1 2 V 3 v 4 v 5 V 6 V 8 v 9 10 11 12 Reading proficiency: An educator wants to construct an 80% confidence interval for the proportion of elementary school children in Colorado who are proficient in reading. Part: 0 / 3 Part 1 of 3 (a) The results of a recent statewide test suggested that the proportion is 0.76. 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 elementary school children is needed to obtain an 80% confidence interval with a margin of error of 0.04. X