Question

If $\frac{x_1+x_2....+x_{20}}{20}=M$ then the value of $\sum _{i=1}^{20}\frac{x_i-M}{20}$ is

• A. $\frac{19M}{20}$
• B. $1$
• C. $0$
• D. $\frac{1}{20}$

Answer 1

The correct option is C $0$

Consider given the expression,

$\Rightarrow \frac{x_1+x_2+.......x_{20}}{20}$

Let,$\frac{x_1+x_2+.......x_{20}}{20}=M$

Now,

$\sum _{i=1}^{20}\frac{x_i-M}{20}=\sum _{i=1}^{20}\frac{\left(\frac{x_1+x_2+.......x_{20}}{20}\right)-M}{20}=\sum _{i=1}^{20}\frac{M-M}{20}=0$

Hence, this is the answer.