Question

$2,10,m,12,4$
A group of $5$ integers is shown above. If the average (arithmetic mean) of the numbers is equal to $m$, find the value of $m$.

• A. $7$
• B. $8$
• C. $9$
• D. $10$
• E. $11$

Answer 1

The correct option is A $7$

We know the average of a group of numbers is the sum of the numbers divided by the number of numbers, we can make an equation:
$\Rightarrow \frac{2+10+m+12+4}{5}=m$
$\Rightarrow 28+m=5m$
$\Rightarrow m-5m=-28$
$\Rightarrow -4m=-28$
$\Rightarrow m=7$