For its three investment centers, Blue Spruce Company accumulates the following data: II III Sales $1,640,000 $3,280,000 $3,280,000 Controllable margin 1,107,000 1,574,400 2,870,000 Average operating assets 4,100,000 6,560,000 8,200,000 Compute the return on investment (ROI) for each center. 1 II III The return on % % investment