11.25 A presently owned machine can last 3 more years, if properly maintained at a cost of $15,000 per year. AOC is $31,000 per year. After 3 years, it can

be sold for an estimated $9000. A replacement costs$80,000 with a $10,000 salvage value after 3 years and an operating cost of $19,000 per year. Different vendors have offered $10,000 and $20,000, respectively, for the current system as trade-in for the re-placement machine. At i = 12% per year, perform a replacement study and determine whether the de-fender should be retained or replaced.Its