Suppose the mean height in inches of all 9th grade students at one high school is estimated. The population standard deviation is 5 inches. The heights of 9 randomly selected students are 65, 70, 66, 75, 60, 69, 75, 75 and 70 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]