Mrs. Martha and her husband, Malcolm, are planning their dream house. The lot for the house sits high
on a hill with a beautiful view of the Appalachian Mountains. The plans show the size of the house to be
3,600 square feet. The average price for a lot and house similar to this one has been $305 per square foot.
Fortunately, Malcolm is a retired employee of a firm who installed furnaces. Having this experience, he
feels he can save money by installing the furnace himself. Mrs. Martha feels she can take care of the
The following average cost information is available from a local bank that makes loans to local
contractors and disperses progress payments to contractors when specific tasks are verified as complete.
22% Excavation and framing complete
8.25% Roof and fireplace complete
9.25% Wiring roughed in
5.50% Plumbing roughed in
5% Siding on
12.50% Windows, insulation, walks, plaster, and garage complete
2.25% Furnace installed (Material and Furnace costs $12050)
7.50% Plumbing fixtures installed
8.50% Exterior paint, light fixtures installed, finish hardware installed
3.75% Carpet and trim installed
7.50% Interior decorating (Material costs $62840)
8.00% Floors laid and finished
a. What is the estimated cost for the Martha’s house if they use contractors to complete the entire
b. Calculate the individual costs of all the tasks stated in above table.
c. Estimate how much money would be saved if the Mrs. Martha and her husband use their talents
to do the related work themselves.