5. A 2,000 square foot house in New Jersey

costs $1,725 each winter to heat with its existing oil-burning furnace. For an investment of $5,000, a natural gas furnace can be installed, and the winter heating bill is estimated to be $1,000. If the homeowners MARR is 6% per year, what is the discounted payback period of this proposed investment? Note: Your saving need to be consider in finding payback period.