Question

The weights in kilogram of $9$ members in a school boxing team are $54,59,x,53,73,49,50,58,45$. If the average is $56$, then $x$ is:

• A. $61kg$
• B. $62kg$
• C. $64kg$
• D. $63kg$

Answer 1

The correct option is D $63kg$

Given weight in $kg$ is: $54,59,x,53,73,49,50,58,45$.

We know, Mean is given by,

$\text{Mean}=\frac{\text{Sum of the elements}}{\text{Total number of elements}}$.

Here, the number of members $=9$.

Also, average weight $=56kg$.

Then,

$⟹$ $56=\frac{54+59+x+53+73+49+50+58+45}{9}$

$⟹$ $56=\frac{441+x}{9}$

$⟹$ $56\times 9=441+x$

$⟹$ $504=441+x$

$⟹$ $x=504-441=63kg$.

Therefore, option $D$ is correct.