4. Suppose that a function z : f(:c,y) has level curves 2 = ung) = constant (2-2, -1, O, 1, 2) on the respective curves just below each of these values shown in the figure. (a) Compute the approximate average value of f in the square S : {(33, y) : 0 g :13 g 2, 0 g y g 2} using evaluation at the 4 midpoints of 4 grid cells each with Am 2 Ag 2 1. Show your midpoints and cells on a rough copy of the figure. (b) How would you improve your estimate? One or two sentence answer needed, no calculations needed. 5. Consider the integral / f \\/:r2 + Z2 dV where D is the region bounded by the paraboloid y = 53122 D and the plane y : 4. Set up but do not evaluate the integral as an iterated integral