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an engineer uses an economic analysis to determine which of two different machin

ID: 1101435 • Letter: A

Question

an engineer uses an economic analysis to determine which of two different machines to purchase. All the machines that are being considered are capable of performing the same task. Assume that the minimum attractive rate of return is 12% compounded monthly. what is the annual worth (EAW)? which is the best economic investment?

machine x; initial cost=8000, estimated life=3years, salvage value=1000, monthly maintanace cost=1500, monthly income=3550

machine y; initial cost=11000, estimated life=3years, salvage value=1500, monthly maintanace cost=1475, monthly income=3475

a) EAWx=669.51, EAWy=807.53; Y is the best investment

b) EAWx=807.53., EAWy=669.51; X is the best investment

c) EAWx=1784.76, EAWy=1646.83; X is the best investment

c) EAWx=1784.76, EAWy=1646.83; Y is the best investment

Explanation / Answer

effective annual rate = (1+12/1200)^12-1 = 12.6825%

monthly interest rate = 12/12 = 1%

for machine X,

to calculate EAW, first we have to calculate the NPV

annual net monthly cashflow = 3550-1500 = $2050

NPV = -8000+2050*PVIFA(1%,36)+(1000/1.01^36)

NPV = -8000+2050*30.1075+(1000/1.01^36) = $54419.30

EAWx = NPV/PVIFA(1,36) = 54419.30/30.1075 = $1784.76

monthly cash flow for Project Y = 3475-1475 = 2000

NPVy = -11000+2000*PVIFA(1%,36)+(1500/1.01^36)

NPVy = -11000+2000*30.1075+(1500/1.01^36) = $50263.387

EAWy = 50263.387/30.1075

EAWy = $1646.83

c) EAWx=1784.76, EAWy=1646.83; X is the best investment