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MHT CET · Maths · Statistics

The variance of first 50 even natural numbers is

  1. A 833
  2. B 473
  3. C \(\frac{437}{4}\)
  4. D \(\frac{833}{4}\)
Verified Solution

Answer & Solution

Correct Answer

(A) 833

Step-by-step Solution

Detailed explanation

\(\begin{aligned} & \text { Variance }=\frac{\sum x_{\mathrm{i}}^2}{\mathrm{n}}-(\bar{x})^2 \\ & =\frac{\left(2^2+4^2+\ldots+100^2\right)}{50}-\left(\frac{2+4+\ldots+100}{50}\right)^2 \\ & =\frac{4\left(1^2+2^2+\ldots .+50^2\right)}{50}-(51)^2 \\ & =4\left(\frac{50 \times 51 \times 101}{50 \times 6}\right)-(51)^2 \\ & =3434-2601 \\ & =833\end{aligned}\)