You work as an estimator for a home improvement contractor. Part of the bid that you are preparing includes a bid to build a fancy deck 10 ft. x 30 ft. for a homeowner. The deck will be over a steeply sloping back yard which requires extra bracing for the posts and a long stairway. Your carpentry estimator used a Parametric estimate of $24.00 per sf. ft. He adjusted it upward by 10% for the difficulty. Are you comfortable with his estimate? How would you check it?