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NDA 2012
Exam
NDA
Year
2012
Subject
Mathematics
Chapter
Statistics

NDA 2012 · Mathematics · Statistics

The algebraic sum of the deviations of 20 observations measured...

The algebraic sum of the deviations of 20 observations measured from 30 is 2. What would be the mean of the observations?

Options

  1. A30
  2. B32
  3. C30.2
  4. D30.1

Correct answer

D. 30.1

Step-by-step solution

Standard deviation =30=30 algebraic sum with deviation =∑xi−h=2=\sum x i-h=2 Mean =∑xi−h20+h=220+30=30+0.1=30.1.\begin{aligned} & \text{ Mean }=\frac{\sum x i-h}{20}+h=\frac{2}{20}+30 \\ & =30+0.1=30.1.\end{aligned}$$
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