NIMCET 2016 Mathematics PYQ — Let be n observations such that and . Then a possible value of n … | Mathem Solvex | Mathem Solvex
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NIMCET 2016 — Mathematics PYQ
NIMCET | Mathematics | 2016
Let x₁, x₂, …, xₙ be n observations such that ∑x₂ = 400 and ∑x = 80. Then a possible value of n among the following is
Choose the correct answer:
A.
10
B.
15
C.
20
(Correct Answer)
D.
8
Correct Answer:
20
Explanation
concept: Variance = ∑(x - μ)²/N, where, μ = mean Variance ≥ 0 ∑x² ≥ μ² Calculation: sum of n observation ∑x = 80 sum of the square of n observation ∑x² = 400 μ = 80/n ∑x² = 400/n ∑x² ≥ μ² 400/n ≥ 80²/n² n ≥ 16
From options, n= 20
Explanation
concept: Variance = ∑(x - μ)²/N, where, μ = mean Variance ≥ 0 ∑x² ≥ μ² Calculation: sum of n observation ∑x = 80 sum of the square of n observation ∑x² = 400 μ = 80/n ∑x² = 400/n ∑x² ≥ μ² 400/n ≥ 80²/n² n ≥ 16
