please show work and explain

A company is deciding to replace major piece of machinery. Four potential alternatives have been identified. Assume 15% interest and determine the following What is the most appropriate Analysis Period? a. Incremental Analysis ( IRR) b. 12 years for Machine 1; 20 years for Machine 2; 60 years for Machine 3; and 30 years for Machine 4 c. The average of the useful lives of the different alternatives, in this case, 30.5 years d. 60 years e. 12 years Which Alternative has the highest Salvage Value in today's dollars? a. Machine 1 and Machine 2 , both the same b. Machine 2, Machine 3 , and Machine 4 c. Machine 3 d. Machine 2