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 6 inches. The heights of 6 randomly selected students are 60 69 68 74 71 and 62 T = 69 Margin of error at 90% confidence level = 23 # 09% confidence interval = [ Ex: 12 34) 12.34 ] smaller value, larger valuel