Mathematics
Mean (Arithmetic Mean)
Quick fact
The mean is so sensitive to outliers that a single billionaire in a room with 99 average people can make the 'average' income in that room appear to be millions of dollars, even though almost everyone earns far less.
Why this is interesting
You've probably used averages your whole life, but did you know that a single extreme value can dramatically shift the average of an entire dataset? That's the power—and the trickiness—of the mean.