InterviewSolution
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InterviewSolution
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Find the mean deviation from mean of the observations: a, a+d, …., (a+2nd).(a) n(n + 1)d^2/3(b) n(n + 1)d^2/2(c) a + n(n + 1)d^2/2(d) n(n + 1)d/(2n + 1)I have been asked this question in an interview for job.This interesting question is from Statistics in division Statistics of Mathematics – Class 11 |
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Answer» RIGHT answer is (d) n(n + 1)d/(2N + 1) To elaborate: Mean = \(\FRAC{1}{n}\) Σ XI = \(\frac{1}{2n+1}\) [a + (a + d) + … + (a + 2nd)] = a + nd ⇒ Mean Deviation = \(\frac{1}{2n+1}\) [2 × d × (1 + 2 + … + n)] = [n (n + 1) (d)]/(2n + 1). |
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