Correct. The given line is written in the form $\displaystyle{y}={m}{x}+{b}\usepackage{cmbright}\Huge\$ . Since $\displaystyle{m}=-\frac{{1}}{{3}}\usepackage{cmbright}\Huge\$ , the slope is $\displaystyle-\frac{{1}}{{3}}\usepackage{cmbright}\Huge\$ . The slope of any perpendicular line would be the negative reciprocal of this slope. Therefore, its slope would be 3.