CUET Preparation Today
CUET
-- Applied Mathematics - Section B2
Probability Distributions
For a random variable X, E(X) = 4 and $E(X^2)=20.$ Then variance of X is
16
2
4
1
The correct answer is Option (3) → 4
$Var(x)=E(x^2)-(E(x))$
$=20-(4)^2$
$=4$
