6.4 Q4.) How much weekly profit (to the nearest dollar) will the agency have if 75 cars are sold per week?


The first integral in the table matches the form in the problem, with
... u = x, a = 2, b = 5.
Then the profit function is
... p(x) = 2(15x-4)/(375)√((2+5x)³) - 1501.09
(Without the added constant, the function p(1) evaluates to about 1.09.)
A graph shows the number of sales required for a $12000 profit is about 47 cars.
Sale of 75 cars per week will result in a profit of about p(75) ≈ $42,263.