CUET Preparation Today
For a probability distribution if $E(X^2)=0.80 $ and $E(X)=0.40 $, then then its standard deviation is ________ . |
0.80 0.60 0.40 0.32 |
0.80 |
The correct answer is Option (1) → 0.80 for any random variable X, the variance is given by - $σ^2=E(X)^2-[E(X)]^2$ $=0.80-(0.40)^2$ $=0.80-0.16=0.64$ $σ$, standard deviation = $\sqrt{0.64}=0.8$ |
