William Brown owns a garage and is contemplating purchasing a tire retreading machine for $12,000. After estimating costs and revenues, William projects a net cash inflow from the retreading machine of $2,640 annually for 13 years. William hopes to earna return of 15% on such investments. What is the present value of the retreading operation? Should William Brown purchase the retreading machine? (For calculation purposes, use 5 decimal places as displayed in the factor table provided (Round answer to 2 decimal places eg. 15.25.) Click here to view the factor table. (a) The present value of the retreading operation is b) William Brown purchase theretreading machine