Which of the following properties of variance is true?
- $V(px)=p^2(V(x); $ if $x$ is random variable and $p$ is constant.
- $V(x-4)=V(x)-V(4);$ if $x$ and $y$ are independent random variables.
- $V(px+z)=p^2(V(x)+z;$ if $x$ is a random variable, $p$ and $z$ are constants.
[$V$ is the symbol that represents Variance.]
- Only (i)
- All are true
- (i) & (iii) are true
- (ii) and (iii) only