If x is the mean of x1, x2, x3, ..., xn, then

Question:

If $\bar{x}$ is the mean of $x_{1}, x_{2}, x_{3}, \ldots, x_{n}$, then $\sum_{i=1}^{n}\left(x_{i}-\bar{x}\right)=?$

(a) $-1$

(b) 0
(c) 1

(d) n − 1

 

Solution:

(b) 0

If $\bar{x}$ is the mean of $x_{1}, x_{2}, x_{3}, x_{4, \ldots} x_{n}$, then we have:

$\sum_{i=1}^{n} x_{i}=\bar{x}$

$\mathrm{O} r$

$\sum_{\mathrm{i}=1}^{\mathrm{n}} \mathrm{x}_{\mathrm{i}}-\overline{\mathrm{x}}=0$

 

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