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.