CHALLENGE ACTIVITY 5.7.1: Confidence intervals for population means 1346866.20 Start Suppose the mean height in inches of all 9th grade students at one high school is 2 estimated. The population standard deviation is 3 inches. The heights of 10 randomly selected students are 65, 63, 72, 69, 72, 61, 74, 74, 68 and 73 = 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] Check Next