Bessel's correction

Bessel's correction is like when you count how many fingers you have on one hand. Let's say you counted 4 fingers, but you actually have 5 fingers on that hand. That's because you forgot to count your thumb!

In statistics, sometimes we want to find the average, or mean, of a group of numbers. We add all the numbers together, then divide by how many numbers there are. But sometimes, like counting fingers, we might forget to count something. And that can make our average, or mean, not quite right.

Bessel's correction helps fix this problem by adjusting the formula we use to find the average, or mean. Instead of dividing by the total number of numbers, we divide by one less than the total number of numbers. This helps make the average, or mean, more accurate.

So, just like counting all your fingers (including your thumb!), Bessel's correction helps us make sure we count all the numbers correctly when finding the average, or mean.