Let the radius of the hemisphere be \(r_1\) units and the radius of the sphere be \(r_2\) units. Therefore, according to the question, \(3\pi r_1^2 = 4\pi r_2^2\) Or, \(\frac{r_1^2}{r_2^2} = \frac{4}{3}\) Or, \(\frac{r_1}{r_2} = \frac{2}{\sqrt{3}}\) Therefore, \(r_1 : r_2 = 2 : \sqrt{3}\)