#### Answer

The percent of decrease is 33.4%.

#### Work Step by Step

The amount of change is $42.8-28.5=14.3$.
$\frac{part}{whole}=\frac{percent}{100}$
$\frac{14.3}{42.8}=\frac{p}{100}$
Cross multiply to solve for p.
$42.8p=(14.3)(100)$
$42.8p\div42.8=1430\div42.8$
$p=33.4112$