dse 2010 doubt

[bhawna]

Let X be normally distributed random variable with mean 0 and variance sigma^2. Then the mean of X^2 is
1. 0
2. Sigma
3.2×sigma
4. Sigma^2

[SoniaKapoor]

var(x)=E(x^2)-(E(x))^2
   sigma^2=E(x^2)-0
=sigma^2