The service division of Raney Industries reported the following results for 2020 Sales $478.000 Variable costs 286.800 Controllable food costs 65.230 Average operating assets 663.000 Management is considering the following independent courses of action in 2021 in order to maximize the return on investment for this division 1 Reduce average operating assets by 5178,500, with no change in controllable margin. Increase sales $129,285, with no change in the contribution margin percentage 2 (a) Compute the controllable margin and the return on investment for 2020 Controllable margin $ Return on investment for 2020