CHALLENGE ACTIVITY 6.2.1: Confidence intervals for population means. 402880.2587626.qx3zqy7 Jump to level 1 1 Suppose the mean height in inches of all 9th grade students at one high school is 2 estimated. The population standard deviation is 5 inches. The heights of 9 randomly selected students are 63, 66, 70, 69, 70, 74, 70, 65 and 73. T = Ex: 12.34 Margin of error at 99% confidence level = Ex: 1.23 99% confidence interval = [ Ex: 12.34 Ex: 12.34 [smaller value, larger value] 2 Check Next Feedback