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NDA 2018
Exam
NDA
Year
2018
Subject
Mathematics
Chapter
Statistics

NDA 2018 · Mathematics · Statistics

An analysis of monthly wages paid to the workers in two firms A and...

An analysis of monthly wages paid to the workers in two firms A and B belonging to the same industry the following result:
The average of monthly wages and variance of distribution of wages of all the workers in the firms A and B taken together are

Options

  1. A₹ 1860,100
  2. B₹ 1750,100
  3. C₹ 1800m,811800 \mathrm{ m}, 81
  4. DNone of above

Correct answer

D. None of above

Step-by-step solution

Combined Average =500×1860+600×17501100=\frac{500 \times 1860+600 \times 1750}{1100}=1800CombinedVarianceCombined Variance=500(81+3600)+600(100+2500)1100=(5×3681)+(6×2600)1100≈3092\begin{aligned} & =\frac{500(81+3600)+600(100+2500)}{1100} \\ & =\frac{(5 \times 3681)+(6 \times 2600)}{1100} \approx 3092 \end{aligned}$
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