Suppose the presence of phosphates in certain waste products dumped into a lake promotes the growth of algae. Rampant growth of algae affects the oxygen supply in the water, so an environmental group wishes to estimate the area of algae growth. The group measures the length across the algae growth (see the figure) and obtains the data (in feet) in the table. X Length X Length 0 50 24 10 12 60 21 20 15 70 20 30 15 80 0 40 27 Use 8 rectangles with bases of 10 feet and lengths measured at the left-hand endpoints to approximate the area of the algae growth. (Give an exact answer. Do not round.) sq ft Algae growth + + x 10 20 30 40 50 60 70 80 Need Help? Read It