Question

If the mean of $5$ observations $x,x+2,x+4,x+6$ and $x+8$ is $11,$ find the value of $x.$

Answer 1

The given observations are $x,x+2,x+4,x+6$ and $x+8.$

Mean of the given observation $=\frac{\text{Sum of total observation}}{\text{Number of observatio}}$

$\frac{x+(x+2)+(x+4)+(x+6)+(x+8)}{5}=11$ [Mean is given as 11]

$\Rightarrow 5x+20=55$

$\Rightarrow 5x=35$

$\Rightarrow x=7$