For example 12 5 6 7
15 9 = 54, three are six numbers in the equation, so there for we use the
six and divide it into 54. 54/6=9, the number 9 is the mean. Although the mean
is not necessarily the best choice of measurement because of the extreme
values.
Q: If the mean is not the best choice, what
would you chose to give the confidence interval?