## Basic College Mathematics (10th Edition)

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. $42.8p=(14.3)(100)$ $42.8p\div42.8=1430\div42.8$ $p=33.4112$