Challenge activities CHALLENGE ACTIVITY 4.2.1: Confidence intervals for population means. 403984.2591602.qx3zay7 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 6 randomly selected students are 71, 70, 74, 67, 75 and 67. = Ex: 12.34 Margin of error at 90% confidence level = Ex: 1.23 90% confidence interval = [ Ex: 12.34 Ex: 12.34 [smaller value, larger value] 1 2 Check Next