What math is use to get the answer for 1.96 where 2 is over the 8 which = 1.39, how did they get that answer. Please give me those step for that small equation.

The mean is the sum of student heights divided by the number of students. 68 + 67 + 67 + 68 + 70 + 72 + 69 + 67 T = = 68.5 8 The margin of error m is equal to z* where z* is the critical z value for the n confidence level, o is the population standard deviation, and n is the number of students. The critical z-value at the 95% confidence interval is z* = 1.96 from the table of critical values. Then, the margin of error is m = z 1.96-2 ~1.39 V8 The 90% confidence interval is given by - m, x + m = 68.5 - 1.39, 68.5 + 1.39 = 67.11, 69.89] Feedback