Question

The variance of α, β and γ is 9, then variance of 5α, 5β and 5γ is

• A. 45
• B. 9/5
• C. 5/9
• D. 225

Answer 1

Answer: (D)

225

Answer 2

When each item of a data is multiplied by $\lambda$, variance is multiplied by $\lambda^{2}$.

Hence, new variance $= 5^{2} \times 9 = 225$.