A piece of onboard equipment has a first cost of $600,000, an annual cost of $92,000, and a salvage value that decreases to zero by $150,000 each year of the equipment's maximum useful life of 5 years. Assume the company's MARR is 10% per year.

a) Determine the ESL (Economic Service Life) by hand

b) Use a spreadsheet with a graph indicating the capital recovery, AOC, and total AW per year to determine the ESL