Answer:
Net present value of purchasing tractor is -$2498.35.
Explanation:
Tractor Cost = $9,000
PV of Year 1 saving = $2,000 ( 1 + 0.07 )^-1 = $1,869.16
PV of Year 2 saving = $2,500 ( 1 + 0.07 )^-2 = $2,183.60
PV of Year 1 saving = $3,000 ( 1 + 0.07 )^-3 = $2,448.89
Net Present Value = ($9,000) + $1,869.16 + $2,183.60 + $2,448.89
Net present value = ($2498.35)