Mathematics
Mean (Arithmetic Average)
Quick fact
The concept of the mean was used by the ancient Babylonians over 4,000 years ago to compute average crop yields, and it was formalized by Greek mathematicians like Pythagoras.
Why this is interesting
You've probably calculated your average test score without thinking twice—but that simple number, the mean, is one of the most powerful tools for understanding the world through data. What makes it so useful, and where does it fall short?