try this data set:
standard deviation: ;you figure it.
Ok, I know your thinking: But it says 5 data points.
do the statistics.
What you are missing is an understanding of numbers. Numbers are symbols, they do not indicate value or meaning. Any statistician can shift the numbers (mean, median, and standard deviation) by changing the scale, or sample range.
Do the same math in these numbers:
29,29, 20, 11,11
same data, shifted. Interesting, isn't it.