Question

The median of a set of eight numbers is $4.5$. Given that seven of the numbers are $7,2,3,4,8,2$ and $1$ find the eighth number and write down the mode of eight numbers.

• A. $4$
• B. $7$
• C. $2$
• D. $1$

Answer 1

The correct option is C $2$

Let the eighth number be $x$.

Then the numbers arranged in ascending order:
$1,2,2,4,7,8,13,x$
Since these are $8$ in number.
Median value $=\frac{\left(\frac{8}{2}\right)thvalue+(\frac{8}{2}+1)thvalue}{2}$
$=\frac{4thvalue+5thvalue}{2}$
$=\frac{4+7}{2}=\frac{11}{2}=5.5$
$\therefore$ Mode $=2$