The demand for a commodity generally decreases as the price is raised. Suppose that the demand for oil (per capita per year) is D(p)=800/p barrels, where p is the price per barrel in dollars. Find the demand when p=55. Estimate the decrease in demand if p rises to 56 and the increase in demand if p is decreased to 54.
The demand D(55) = .
The decrease in demand = barrels.
The increase in demand = barrels.