Averages Mask Reality

A statistician drowns crossing a river that is "on average" three feet deep — because one section is ten feet deep. Averages can mask dangerous variation. When someone quotes an average salary, an average test score, or an average return, always ask: what does the distribution actually look like? The spread matters as much as the center.

The three most common averages — mean, median, and mode — can tell wildly different stories about the same data. In a company where the CEO earns $10 million and 99 employees earn $50,000, the mean salary is $149,500 — a number nobody actually earns.