Nancy Jackson operates a popular summer camp for elementary school children. Projections for the current year are as follows: Sales revenue $7,860,000 Operating income $693,250 Average assets $3,952,000 The camp's weighted-average cost of capital is 10%, and Nancy requires that all new investments generate a return on investment of at least 14%. The camp's current tax rate is 30%. At last week's advisory board meeting. Nancy told the board that she had up to $70,000 to invest in new facilities at the camp and asked them to recommend some projects. Today the board's president presented Nancy with the following list of three potential investments to improve the camp facilities. Playground Swimming Pool Gym Incremental operating income $1,740 $6,290 $3,920 Average total assets 14,500 37,000 24,500 (a) Calculate the return on investment, residual income, and economic value added for each of the three projects. (Enter negative