For a random variable X, the variance Var(X) equals

Question

Accepted Answer

C. {'text': 'E(X²) − [E(X)]²', 'label': 'C'}

1. Variance measures the spread of X around its mean.
2. By definition Var(X) = E[(X − μ)²].
3. Expanding: Var(X) = E(X²) − 2μE(X) + μ² = E(X²) − μ² = E(X²) − [E(X)]².
4. This is the standard computational form for variance.
_Source: NCERT Class 12 Mathematics, Ch 13 "Probability", §13.6_

Answer

{'text': 'E(X)²', 'label': 'A'}

Answer

{'text': '[E(X)]² − E(X²)', 'label': 'B'}

Answer

{'text': 'E(X) − E(X²)', 'label': 'D'}