One of four new techniques, or the current method, can be used to control mildly irritating chemical fume leakage into the surrounding air form a mixing machine. The estimated costs and benefits (in the form of reduced lost time due to employee poor health compared with the current situation) are given in table 4 for each of the new methods. Assuming that all the methods have a ten-year life with zero salvage value, DETERMINE which one should be selected of the five methods, using a MARR of 15% per year and the BC method. STATE any assumptions that you make. Estimated costs and benefits Technique Installed cost, $ Average operating cost, S/year10,000 Benefits, S/year 19,000 12,000 20,000 25.000 9,000 19,000 33,000 11,000 22,000 15,000 15,000