Determining missing items in return on investment computation One item is omitted from each of the following computations of the return on investment: Return on Investment Profit Margin Investment Turnover 15 % 10 % X (a) (b) 12 % X 0.75 15 % X 1.5 (c) 20 % 14 % X (d) (e) 15 % 1.8 Determine the missing items identified by the letters as shown above. If required, round your answers to two decimal places. (a) % (b) (c) (d) % %