Consider the two air conditioning systems detailed below.

System 1 System 2 First cost, $ 10,000 17,000 Annual operating cost, $/year 600 150 Salvage (disposal) value, $ 100 300 New compressor and motor cost at midlife, $ 1,750 3,000 Life, years 8 12 Use AW analysis to determine the sensitivity of the economic decision to MARR values of 4%, 6%, and 8%. Work this problem

(a) by hand and

(b) by spreadsheet.