The graph of the function fis given. y = R( x) 11.4 X (a) By reading values from the given graph of f, use five rectangles to find a lower estimate for the area under the given graph of f, the x-axis, and the lines x = 0 and x = 10. (Round your answer to one decimal place.) Sketch the rectangles to illustrate the estimate. y = Ax y = RX) y = f(x) y = R(x) O A V 18.8 By reading values from the given graph of f, use five rectangles to find an upper estimate for the area under the given graph of f, the x-axis, and the lines x = 0 and x = 10. (Round your answer to one decimal place.) Sketch the rectangles to illustrate the estimate. y = f(x) = RX) y = R(x) y = RX) O O (b) Find new estimates using ten rectangles in each case. (Round your answers to one decimal place.) lower estimate 13.1 upper estimate 16.8