$.$ TXY Inc. recently purchased a new delivery truck. The new truck cost $$25,000.,$ and it is expected to generate net after$-$tax operating cash flows of $$7,500$ per year. The truck has a $4-$year expected life. The expected salvage values after tax adjustments for the truck are as follows.

Year Annual Operating Cash Flow Salvage Value

$0-25,00025,000$

$17,50019,500$

$27,50015,000$

$37,50013,000$

$47,5000$

The company$$s cost of capital is $10\%.$ Should the firm operate the truck until the end of its $4-$year physical life? If not, then what is the optimal economic life? Make sure you show the NPV for various economic life? Please explain and use finance calculator to solve