x= margin of error @ 90% confidence level = 90% confidence interval = (smaller value) (larger value)

2.1 35 CHALLENGE ACTIVITY 5.7.1: Confidence intervals for population means. 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 5 inches. The heights of 7 randomly selected students are 73, 65, 67, 71, 64, 70 and 71. t = 68.71 Margin of error at 90% confidence level = EX: 1.28+ 90% confidence interval = [ Ex: 12 34 Ex. 12.34 ] [smaller value, larger value] Check