# What is uncentered variance and how it becomes equal to mean square in Adam?

In this statement, the author is talking about uncentered variance and how it becomes equal to the square of the mean.

I want to understand what exactly is uncentered variance? (because if I consider the general equation of variance $$\dfrac{(\text{obs-mean})^2}{(n-1)}$$ then it is not making sense to me the removing mean will lead to the definition of uncentered variance as we need a point around which we are calculating variance and here mean is that point)

Also if we are making mean=0(not subtracting mean from obs) then if I consider this as uncentered mean (For me it is variance around 0) then it is becoming hard to understand how this will lead to uncentered $$\text{variance = mean}^2$$

• Hello. Rather than providing a screenshot of the excerpt that you're quoting, it would be better if you can copy and paste the text directly into your post.
– nbro
Oct 22, 2021 at 13:45
• Thanks for the suggestion. I'll follow it next time. Just curious to know what difference text makes in comparison to screenshot? Oct 22, 2021 at 17:10