easiest way to approach the subject of

**summary statistics**is to focus on what we have and what we want to achieve:

- We have a set of observations which we want to summarize.
- We want to communicate as much as possible as simply as possible.

- a measure of location, or central tendency, like the arithmetic mean
- a measure of statistical dispersion like the standard deviation
- a measure of the shape of the distribution like skewness or kurtosis

The Gini coefficient was originally developed to measure income inequality, but can be used for other purposes as well.

back to statistical theory -- summarizing statistical data