MCQ
Variance of $^{10}C_0$ , $^{10}C_1$ , $^{10}C_2$ ,.... $^{10}C_{10}$ is 
  • A
    $\frac{{10.\,{}^{20}{C_{_{10}}} - {2^{10}}}}{{100}}$
  • B
    $\frac{{11\,{}^{20}{C_{_{10}}} - {2^{10}}}}{{11}}$
  • C
    $\frac{{10.\,{}^{20}{C_{_{10}}} - {2^{20}}}}{{100}}$
  • $\frac{{11.\,{}^{20}{C_{_{10}}} - {2^{20}}}}{{121}}$

Answer

Correct option: D.
$\frac{{11.\,{}^{20}{C_{_{10}}} - {2^{20}}}}{{121}}$
d
Variance $=\frac{\Sigma \mathrm{x}_{\mathrm{i}}^{2}}{\mathrm{n}}-\left(\frac{\Sigma \mathrm{x}_{\mathrm{i}}}{\mathrm{n}}\right)^{2}$

$=\frac{^{20} \mathrm{C}_{10}}{11}-\left(\frac{2^{10}}{11}\right)^{2}$

$=\frac{11 \cdot^{20} \mathrm{C}_{10}-2^{20}}{121}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

If $5\cos 2\theta + 2{\cos ^2}\frac{\theta }{2} + 1 = 0, - \pi < \theta < \pi $, then $\theta = $
$\int {\frac{{(\sin \theta + \cos \theta )}}{{\sqrt {\sin 2\theta } }}} d\theta = $
Area enclosed by the graph of the function $y$ = $ln^2x -1$ lying in the $4^{th}$ quadrant is
Consider an experiment of tossing a coin repeatedly until the outcomes of two consecutive tosses are same. If the probability of a random toss resulting in head is $\frac{1}{3}$, then the probability that the experiment stops with head is.
A straight line through origin bisect the line passing through the given points $(a\cos \alpha ,a\sin \alpha )$ and $(a\cos \beta ,a\sin \beta )$, then the lines are
The solution of the equation $\left[ {\begin{array}{*{20}{c}}1&0&1\\{ - 1}&1&0\\0&{ - 1}&1\end{array}} \right]\,\left[ \begin{array}{l}x\\y\\z\end{array} \right] = \left[ \begin{array}{l}1\\1\\2\end{array} \right]$ is $(x,y,z)$=
The value of the limit$\lim _{x \rightarrow \frac{\pi}{2}} \frac{4 \sqrt{2}(\sin 3 x+\sin x)}{\left(2 \sin 2 x \sin \frac{3 x}{2}+\cos \frac{5 x}{2}\right)-\left(\sqrt{2}+\sqrt{2} \cos 2 x+\cos \frac{3 x}{2}\right)}$ is.$ . . . . . $
Let $X = \{ 1,\,2,\,3,\,4,\,5\} $ and $Y = \{ 1,\,3,\,5,\,7,\,9\} $. Which of the following is/are relations from $X$ to $Y$
If the sum of the two roots of the equation $4{x^3} + 16{x^2} - 9x - 36 = 0$ is zero, then the roots are
Five numbers are in $A.P.$, whose sum is $25$ and product is $2520 .$ If one of these five numbers is $-\frac{1}{2},$ then the greatest number amongst them is