If the arithmetic mean of the series x₁, x₂, …, xₙ is 1, then the arithmetic mean of x₁/k, x₂/k, …, xₙ/k (k > 0) is:
A1/k
Bk
C2/k
D2k
Answer & Solution
Correct answer: A. 1/k
1. Mean of original series = (Σxᵢ)/n = 1, so Σxᵢ = n.
2. New mean = (Σ (xᵢ/k))/n = (Σxᵢ)/(kn) = n/(kn).
3. = 1/k.
_Source: RRB Group D CEN-02/2018 PYQ, Q.25._
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