Question

The mean of the following data is $8$:

x	$3$	$5$	$7$	$9$	$11$	$13$
y	$6$	$8$	$15$	$p$	$8$	$4$

The value of $p$ is:

• A. $23$
• B. $25$
• C. $24$
• D. $21$

Answer 1

The correct option is B

$25$

Find the value of $p$:

x	y	xy
$3$	$6$	$18$
$5$	$8$	$40$
$7$	$15$	$105$
$9$	$p$	$9p$
$11$	$8$	$88$
$13$	$4$	$42$
Total	$41+p$	$303+9p$

We know that, $mean=\frac{sumofallobservation}{totalnumberofobservation}$

Given that, $mean=8$

$\begin{array}{rcl}\frac{303+9p}{41+p}& =& 8\\ 303+9p& =& 328+8p\\ p& =& 25\end{array}$

Hence, option (b) is correct.