\(p^{\frac{1}{3}}\) = \(\frac{\sqrt[3]{q}}{r}\) cross multiply \(p^{\frac{1}{3}}\) = \(\frac{q^{1/3}}{r}\) r\(p^{\frac{1}{3}}\) = \(q^{\frac{1}{3}}\) take the cube of both sides \((rp^{\frac{1}{3}})^3\) = \((q^{\frac{1}{3}})^3\) \(r^3p^{\frac{3}{3}}\) = \(q^{\frac{3}{3}}\) \(r^3\)p = q ∴ q = p\(r^3\)