Question

The numbers $3,5,7,4$ have frequencies $x,x+4,x-3,x+8.$ If their arithmetic mean is $4$, the value of $x$ is

• A. $\frac{5}{3}$
• B. $\frac{7}{4}$
• C. $\frac{2}{3}$
• D. none of these

Answer 1

The correct option is A $\frac{5}{3}$

Here $\frac{3\left(x\right)+5(x+4)+7(x-3)+4(x+8)}{\left(x\right)+(x+4)+(x-3)+(x+8)}=4$ (given)

$\Rightarrow \frac{19x+31}{4x+9}=4\Rightarrow x=\frac{5}{3}$