The quantity, q, of a certain skateboard sold depends on the selling price,p, in dollars, so we write (1 = f(p). You are given that = , and = . (120) 17200 f'(120) 110 V Your answer is correct. X Your answer is incorrect. dR (b) The total revenue, R, earned by the sale of skateboards is given by R = pq. Find dp p=120 Enter the exact answer. dR i 110 dp p=120 eTextbook and Media Hint Assistance Used Find the derivative of the revenue using the product rule.Your answer is partially correct. dR (c) What is the sign of ? If the skateboards are currently selling for $120, what happens to revenue if the price is dp lp=120 increased to $121? Enter the change as a positive value. > 0. dp p=120 If the price is increased to $121, revenue increases by about $ 110 e Textbook and Media Hint Assistance Use dR Use the answer from part (b) to determine the sign of . Use the fact that the derivative gives the approximate dp lp=120 change in R(p) when p changes by 1 to approximate how much the value of the function will change