# what is this formula for

#### rbcc

##### Junior Member
Hi,

I have a quick question, is this a formula for variance?

$$\displaystyle \Sigma \ X^2$$ $$\displaystyle -$$ $$\displaystyle \frac{(\Sigma \ {X)}^2}{N}}$$

Thank you!

#### tkhunny

##### Moderator
Staff member
...Only if you divide by N.