If-i-1-10-x-i-4-60-then-find-the-value-of-x-

Question Number 93691 by Aniruddha Ghosh last updated on 10/Jun/20

If \underset{i = 1}{\sum^{10}} (x_{i} + 4) = 60 then find the value of \bar{x} .

Commented by hknkrc46 last updated on 15/May/20

\underset{i = k}{\sum^{m}} c = (m - k + 1) c

c = x + 4; m = 10; k = 1

\Rightarrow \underset{i = 1}{\overset{10}{Σ}} (x + 4) = (10 - 1 + 1) (x + 4) = 60

\Rightarrow 10 (x + 4) = 60 \Rightarrow x + 4 = 6 \Rightarrow x = 2

Commented by i jagooll last updated on 14/May/20

\underset{i = 1}{\sum^{10}} (x_{i} + 4) = 60 .

Commented by Aniruddha Ghosh last updated on 10/Jun/20

right. it was by mistake

Answered by Aniruddha Ghosh last updated on 14/May/20

\underset{i = 1}{\sum^{10}} (x + 4) = x_{1} + x_{2} + x_{3} + \dots . + x_{10} + (4 \times 10) = 60

\Rightarrow x_{1} + x_{2} + \dots \dots \dots . . + x_{10} = 60 - 40

\Rightarrow x_{1} + x_{2} + \dots \dots \dots . . + x_{10} = 20

∴ \bar{x} = \frac{x_{1} + x_{2} + x_{3} + \dots . . + x_{10}}{10 (frequency)}

= \frac{20}{10}

= 2