Use nite approximation to estimate the area under the graph of Ex) =x2 and above the graph of x} = i] from x0 = l] to x\" = 4 using i} a lower sum with [we 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 afequal width is D square units. (Simplify your answer. Type an integer or a decimal.)