Question

Mark the correct alternative in the following question:
Let X be a discrete random variable. Then the variance of X is                

 

 

Options

• E(X²)      

• E(X²) + (E(X))²    

• E(X²) - (E(X))²        

• \[\sqrt{E\left( X^2 \right) - \left( E\left( X \right) \right)^2}\]

Answer 1

Since, the variance of a discrete random variable X is given by:

Var(X) = E(X²)  - (E(X))²