CHALLENGE ACTIVITY 6.2.1: Confidence intervals for population means. 402294.2602416.qx3zqy7 Jump to level 1 Suppose the mean height in inches of all 9th grade students at one high school is estimated. The population standard deviation is 2 inches. The heights of 7 randomly selected students are 66, 60, 60, 69, 60, 65 and 72. x = Ex: 12.34 Margin of error at 95% confidence level = Ex: 1.23 95% confidence interval = [ Ex: 12.34 Ex: 12.34 [smaller value, larger value] 2 Check Next