#### Answer

$\frac{1500}{1580}$

#### Work Step by Step

To determine what fraction of affiliates are in the US you must first find the total number of affiliates.
$1500+80=1580$
A fraction represents $\frac{part}{whole}$, so if 1500 affiliates are in the US the fraction that are in the US is $\frac{1500}{1580}$