Incorrect. Use the joint variation equation $\displaystyle{y}={k}{x}{z}\usepackage{cmbright}\Huge\$ , and substitute the given information: $\displaystyle{160}={k}{\left({4},{000}\right)}{\left({2}\right)}\usepackage{cmbright}\Huge\$ . Solve for k. Substitute k, $\displaystyle{x}={5},{000}\usepackage{cmbright}\Huge\$ , and $\displaystyle{z}={2}\usepackage{cmbright}\Huge\$ in the joint variation equation to determine y (the amount of interest earned).