# Estimating Var(s2)

In 20th week,lecture named “Recap and statistics of s2”. While estimating Var(s2) why did we
squared the constant “(n-1)/sigma2” when we took it out of the Var term.
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Hi @sarthak511,
Can you share a timestamp or a reference image please?

In the screenshot, this formula is already given by sir:

As per the formula, when you take a constant out of the variance bracket, it gets squared as variance is actually a degree 2 polynomial.

If you want to know how this formula came to be, then you will have to scroll through previous lectures where this formula derivation was explained.

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i m sorry, i missed .

and yes Thank you.