The means and variance of $n$ observations $x_{1},x_{2},x_{3},\ldots,x_{n}$ are 5 and 0 respectively. If $\sum_{i = 1}^{n}{x_{i}^{2} = 400}$, then the value of $n$ is equal to

Question

Dr. Abubacker · Accepted Answer

(d)
$\overline{x} = 5$
Variance =$\frac{1}{n}\ \Sigma x_{i}^{2} - \left( {\overline{x}}^{2} \right)$
$0 = \frac{1}{n}.400 - 25$
$\Rightarrow n = \frac{400}{25}$
$= 16$

Q. The means and variance of $n$ observations $x_{1},x_{2},x_{3},\ldots,x_{n}$ are 5 and 0 respectively. If $\sum_{i = 1}^{n}{x_{i}^{2} = 400}$, then the value of $n$ is equal to

Explanation

Reviewed by Dr. Abubacker

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