Use nite approximation to estimate the area under the graph of f(x) = 7x2 and above the graph of f(x) = 0 from x0 = 0 to xn = 16 using i) a lower sum with two rectangles of equal width. ii) a lower sum with four rectangles of equal width. iii) an upper sum with two rectangles of equal width. iv) an upper sum with four rectangles of equal width. The estimated area using a lower sum with two rectangles of equal width is El square units. (Simplify your answer. Type an integer or a decimal.) The estimated area using a lower sum with four rectangles of equal width is D square units. (Simplify your answer. Type an integer or a decimal.) The estimated area using an upper sum with two rectangles of equal width is D square units. (Simplify your answer. Type an integer or a decimal.) The estimated area using an upper sum with four rectangles of equal width is D square units. (Simplify your answer. Type an integer or a decimal.)