1) If the marginal revenue function for a company is R' (x) = -0.05x + 70, and if the company has sold 50 items already, find the additional revenue that will be earned by selling the next 60 items. Youbong 2) If a company has a marginal cost function C' (x) = 0.04x+9vx , what is the additional cost of producing 325 more items if 900 have already been made? 3) The rate of increase in consumption in the United States of mineral water (in millions of quarts per year) is given by the function f (t) =0.7t +1.6, where t is the number of years since 1996. How many quarts of mineral water were consumed between 2002 and 2009