Mean, Median & Mode

Nine people in a bar each earn $40,000 a year. In walks a billionaire earning $1,000,000,000. The average income is now about $100 million — but not one person in that bar lives like a hundred-millionaire. The mean chased the outlier; the median, the person in the middle, barely moved. "Average" is not one number — it's three, and the one you pick changes the story.