# Variance

• August 24th 2013, 06:47 AM
downthesun01
Variance
$\\Var[X]\\\\=(X-\mu)^{2}\\\\=X^{2}-2XE[X]+E[X]^{2}\\\\=E[X^2]-E[X]^2$

How does the third line reduce into the fourth line?

Nevermind, I read it wrong. Thanks