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MHT CET · Maths · Statistics

If 1 is added to first 10 natural numbers, then variance of the numbers so obtained is

  1. A 8.25
  2. B 3.87
  3. C 6.5
  4. D 2.87
Verified Solution

Answer & Solution

Correct Answer

(A) 8.25

Step-by-step Solution

Detailed explanation

We have to find variance of numbers \(2,3,4, \ldots ., 11\).
Here \(\overline{\mathrm{x}}=\frac{2+3+4+\ldots+11}{10}=\frac{65}{10}=6.5\)
Variance \(=\frac{\sum\left(\mathrm{x}_{\mathrm{i}}-\overline{\mathrm{x}}\right)^2}{\mathrm{n}}\)
\( \begin{aligned} & =\frac{\left[(-4.5)^2+(-3.5)^2+(-2.5)^2+(-1.5)^2+(-0.5)^2\\+(0.5)^2+ (1.5)^2+(2.5)^2+(3.5)^2+(4.5)^2\right]}{10}\end{aligned}\)
\(=\frac{2(20.25+12.25+6.25+2.25+0.25)}{10}=\frac{41.25}{5}=8.25 \)