National EMSC Data Analysis Resource Center
Measures of center are some of the most important descriptive statistics you can get.
In our society, we always want to know the "average" of everything: the average age, average number, average speed, etc. etc. It helps give us an idea of what the "most" common, normal, or representative answers might be. Essentially, by getting an average, what you are really doing is calculating the "middle" of any group of observations. There are three measures of center that are most often used: