Answer:
a) incremental net income
net income year 1 = ($16,500 - $3,500 - $8,000) x 0.65 = $3,250
net income year 2 = ($17,000 - $3,600 - $8,000) x 0.65 = $3,510
net income year 3 = ($17,500 - $3,700 - $8,000) x 0.65 = $3,770
net income year 4 = ($14,500 - $2,900 - $8,000) x 0.65 =$1,340
b) incremental net cash flow
cash flow year 1 = [($16,500 - $3,500 - $8,000) x 0.65] + $8,000 - $430 = $10,820
cash flow year 2 = [($17,000 - $3,600 - $8,000) x 0.65] + $8,000 - $480 = $11,030
cash flow year 3 = [($17,500 - $3,700 - $8,000) x 0.65] + $8,000 - $380 = $11,390
cash flow year 4 = [($14,500 - $2,900 - $8,000) x 0.65] + $8,000 + $1,670 = $12,010
c) project's NPV
NPV = -$32,380 + $10,820/1.13 + $11,030/1.13² + $11,390/1.13³ + $12,010/1.13⁴ = $1,093.13