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Question 380013
JEE Mathematics · Hard

Statistics: Mixed MCQ

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MixedHardQuestion 380013

Question

If variance of n observations xᵢ is σ², then variance of axᵢ + b is:
  1. A
    a²σ²
    Correct
  2. B
    σ²
  3. C
    aσ² + b
  4. D
    (aσ+b)²

Correct answer

a²σ²

Explanation

Shifting by b (adding constant) doesn't change variance. Scaling by a: Var(aX+b) = a²Var(X) = a²σ². Standard deviation becomes |a|σ.

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