3. [-/1 Points] DETAILS MY NOTES PRACTICE ANOTHER (a) Estimate the volume of the solid that lies below the surface z = 3 + x2 + 3y and above the rectangle R = [1, 2] x [0, 3]. Use a Riemann sum with m = n = 2 and choose the sample points to be lower left corners. (Round your answer to three decimal places.) (b) Use the Midpoint Rule to estimate the volume in part (a). (Round your answer to three decimal places.) Need Help? Read It Submit Answer1. [0.5/1 Points] DETAILS PREVIOUS ANSWERS Estimate the volume of the solid that lies below the surface z = xy and above the following rectangle. R = ( X, y) | 4 5 x 5 10, 6 sys 10 (a) Use a Riemann sum with m = 3, n = 2, and take the sample point to be the upper right corner of each square. 1728 (b) Use the Midpoint Rule to estimate the volume of the solid. 1334 X Need Help? Read It Master It