4. Poly-Chem Plastics is considering two types of injection molding machines -hydraulic and electric. The hydraulic press (HP) will have a first cost of $600,000, annual costs of $200,000, and a salvage value of $70,000 after 5 years. Electric machine technology (EMT) will have a first cost of $800,000, annual costs of $150,000, and a salvage value of S130,000 after 5 years. a) Use an AW-based rate of return equation to determine the ROR on the increment of investment between the two. b) Determine which machine the company should select, if the MARR 16% per year c) Plot the AW versus i graph using spreadsheet for each alternative's cash flows, and utilize it to determine the largest MARR that will justify the EMT extra investment of $200,000