For its three investment centers, Gerrard Company accumulates the following data: I II III Sales $1,925,000 $4,062,000 $3,986,000 Controllable margin 1,109,020 2,537,280 4,253,200 Average operating assets 5,041,000 7,929,000 12,152,000 Compute the return on investment (ROI) for each center.