Question

Find the mean of the following $10$ observations:
$23,22,22,5,5,20,20,20,23,22$.

• A. $14.5$
• B. $18.2$
• C. $16.5$
• D. $7.6$

Answer 1

The correct option is B $18.2$

The frequency table of the above observations can be obtained as below:

$X_i$	$f_i$	$X_i{f}_i$
$5$	$2$	$10$
$20$	$3$	$60$
$22$	$3$	$66$
$23$	$2$	$46$
	$\Sigma f_i=10$	$\Sigma f_i{x}_i=182$

We know, Mean is given by,

$\therefore Mean=\frac{\Sigma f_i{x}_i}{\Sigma f_i}=\frac{182}{10}=18.2$.

Thus, option $B$ is correct.