CUET Preparation Today
CUET
-- Mathematics - Section A
Probability
For a random variable X, E(X) = 3 and $E(X)^2 =11,$ then variance of X is :
8
5
2
1
The correct answer is Option (3) → 2
$E(X) = 3$ and $E(X)^2 =11$
so $σ^2=E(X)^2-(E(X))^2$
$=11-3^2=11-9$
(variance) $σ^2=2$
