\frac{P_{1}}{P_{2}} = \frac{\frac{380^2}{2R}}{\frac{2\cdot 220^2}{R}} = 
\frac{\frac{(220\cdot \sqrt{3})^2}{2R}}{\frac{2\cdot 220^2}{R}} = \frac{\frac{3}{2}}{\frac{2}{1}} = 0.75