Glossary term
Mean
The arithmetic average: add the values and divide by how many values there are.
Visual intuition
values
2
4
9
share total
mean
5
5
5
2 + 4 + 9 becomes 5 each
The mean is what each value would get if the total were shared equally.
Formula
sum(values) / n
Example
For 2, 4, and 9, the mean is (2 + 4 + 9) / 3 = 5.
How It Works
The mean answers a sharing question: if the total were spread equally across every observation, what would each one get? It is useful when totals matter, but it can move sharply when a few values are very large or very small.
