The probability distribution of a random variable X is given below :
Then, Var $\left(\frac{X}{2}\right)$ is : |
0.368751 0.361875 0.36758 0.369822 |
0.361875 |
The correct answer is Option (2) → 0.361875 As, $Var(aX)=a^2\,Var(X)$ $Var(\frac{X}{2})=(\frac{1}{2})^2\,Var(X)=\frac{1}{4}\,Var(X)$ and, $Var(X)=E(X^2)-[E(X)]$^2$ $=(0+0.25+0.6+0.6+0.6)-(0+0.25+1.2+1.8+2.4)$ $=5.05-(2.05)^2$ $=1.4475$ $∴Var(\frac{X}{2})=\frac{1}{4}×1.4475=0.361875$ |