Suppose the mean height in inches of all I3th grade students at one high school is estimated. The population standard deviation is 5 inches. The heights of 9 randomly selected students are 74. 31.74, 72. 61,62; t}, 68 and 1_ E = Ex: 12.34 Margin of error at 90% condence level = E: 1.23 90% condence interval = [ Ex: 12.34 1 Ex: 12.34 ] [smaller value, larger value]