Let X be a discrete random variable. Then the variance of X is: - Vidyadip

MCQ

Let X be a discrete random variable. Then the variance of X is:

A
E(X²)
B
E(X²) + (E(X))²
C
E(X²) - (E(X))²
D
$\sqrt{\text{E}(\text{X}^2)-(\text{E}(\text{X}))^2}$

✓

Answer

E(X²) - (E(X))²

Solution:

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

Var(X) = E(X²) - (E(X))²

Hence, the correct alternative is option (c).

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