Question

The mean of 8 variates is 10.5 . If 7 of them are 3, 15, 16, 18, 14, 34 and 7. Find the 8th variate.

Answer 1

Given that seven out of eight variables are 3, 15, 16, 18, 14, 34, and 7.

Now,

The mean of the 8 variables is 10.5

So,

A total of 8 variables is:

$10.5\times8=84$

Now,

Sum of the seven variables is:

$3+15+16+18+14+34+7=107$

Then,

$\begin{gathered} 107+x=84 \\ x=84-107 \\ x=-23 \end{gathered}$