If controllable margin is $300000 and the average investment center operating assets are $4000000, the return on investment is 10%6 8% 13.33% 133% Crane Company had the following operating data for the current year: sales, $470000; contribution margin, $117000; total fixed costs (controllable), $50000; and average total operating assets, $240000. If management is able to improve its contribution margin by $17000 and hold its fixed costs constant. what would Crane's ROI be for the year? 28% 35% 49%. 18%