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 3 inches. The heights of 9 randomly selected students are 75, 65, 60, 61, 66, 65, 62, 72 and 73. Er = 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