Two alternative replacement machines are being consided to replace a current one. Machine A has a first cost of $75,200 and its salvage value at the end of six years of estimated service life is $21,000. The operating costs of this machine are estimated to be $6,800 per year. Machine B has a first cost of $44,000, and its salvage value at the end of six years' service is estimated to be negligible. The annual operating costs will be $11,500. Compare these two using a present worth criteria at i = 13%.