$\displaystyle{3},{200}\ \text{ pounds}+{5},{100}\ \text{ pounds}+{700}\ \text{ pounds}={9},{000}\ \text{ pounds}\usepackage{cmbright}\Huge\$ . Convert pounds to tons:

$\displaystyle\frac{{{9},{000}\ \text{ pounds}}}{{1}}\cdot\frac{{{1}\ \text{ ton}}}{{{2},{000}\ \text{ pounds}}}={4}\frac{{1}}{{2}}\ \text{ tons}\usepackage{cmbright}\Huge\$