Correct Answer - Option 1 : 20
Concept:
Variance: Let xi for i = 1, 2, 3, …, n be observations then variance is given as:
\(\rm \sigma^2 = \frac{\sum_{i=1}^n (x_i-\bar{x})^2}{n}\)
Properties of variance:
- Var(X + C) = Var(X), where C is a constant.
- Var(CX) = C2 × Var(X), where C is a constant.
Calculation:
Given: Var(X) = 5
Each observation is multiplied by 2.
So, new variance = Var(2X)
= 22 × 5
= 20