JEE Mathematics · Hard

Statistics: JEE Advanced MCQ

Solve this quality-checked JEE multiple-choice question, then review the correct answer and explanation.

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JEE AdvancedHardQuestion 380010

Question

If Σxᵢ = 60, Σxᵢ² = 480, n = 10, then the standard deviation is:
  1. A
    √(480/10 − (60/10)²) = √(48−36) = √12
  2. B
    √12
  3. C
    2√3
  4. D
    All of A, B, C are same
    Correct

Correct answer

All of A, B, C are same

Explanation

σ² = Σxᵢ²/n − (Σxᵢ/n)² = 480/10 − (6)² = 48 − 36 = 12. σ = √12 = 2√3 ≈ 3.46. All three expressions represent the same value.