Learn How to Calculate Var(Y) and Var(Y2) with Statistics Equation Help"

[DavidLiew]

If Var(Y)=$$\sigma^2$$, then Var ( Y² ) = ?

 

[statdad]

$$vary(Y^2) = E(Y^4) - E(Y^2)$$

(same basic patten for the random variable $$Y^2$$ as for any other random variable).

 

[mathman]

$$vary(Y^2) = E(Y^4) - E(Y^2)$$

(same basic patten for the random variable $$Y^2$$ as for any other random variable).

should be
$$vary(Y^2) = E(Y^4) - (E(Y^2))^2$$

 

[statdad]

Crap - yes, mathman is correct. Time to stop posting for a while.

 

[blue_raver22]

If Var(Y)=\sigma^2, then Var(Y2) would also be equal to \sigma^2. This is because when calculating the variance of a variable, the squared values are used. Therefore, squaring Y would result in the same value as squaring Y2. Additionally, the variance is a measure of how much a set of data values vary from the mean, and squaring a variable does not change its variability. Therefore, Var(Y2) would be equal to \sigma^2, just like Var(Y).