Variance formulaHardQuestion 380009
Question
Variance = (Σx²/n) − (x̄)². This formula shows:
- AVariance = mean of squares − square of meanCorrect
- BVariance = mean − standard deviation
- CVariance = range²
- DVariance = median²
Correct answer
Variance = mean of squares − square of mean
Explanation
Alternative variance formula: σ² = (Σxᵢ²/n) − (x̄)². This is computationally easier than finding deviations from mean. Derived by expanding Σ(xᵢ−x̄)²/n.