CHALLENGE ACTIVITY 3.2.1: Confidence intervals for population means. 402892.2536986.qx3zqy7 Jump to level 1 1 Suppose the mean height in inches of all 9th grade students at one high school 2 is estimated. The population standard deviation is 4 inches. The heights of 8 randomly selected students are 74, 74, 70, 65, 66, 63, 71 and 66. D = Ex: 12.34$ Margin of error at 99% confidence level =Ex: 1.23$ 99% confidence interval = [Ex: 12.340 , Ex: 12.34$ ] [smaller value, larger value] 2 Check Next Feedback