Question 23 1.34 pts Rhein Manufacturing recorded operating data for its auto accessories division for the year. Sales $750,000 Contribution margin 150.000 Total direct fixed costs 90,000 Average total operating 400,000 assets How much is ROI for the year if management is able to identify a way to improve the contribution margin by $30,000, assuming fixed costs are held constant? 12.0% 45.0% 15.0% 22.5%