Answer
$x\approx23.08$
Work Step by Step
We can set the cross products of the given proportion equal to each other and then solve for the unknown variable.
$15\times100=x\times65$
$1500=65x$
Divide both sides by 65.
$\frac{1500}{65}=\frac{65x}{65}$
$x\approx23.08$