Find the average value of y on the region D that is bounded above by the parabola y = 4 - x2 and below by the x-axis. Does this question makes sense? I know the formula for the average values function : 1/(A(x)) * doubleIntegralOf F(x,y)DA But its says above the parabola and below the x-axis, does that contradict each other? There is no explanation in the answer but here it is : The area of the region is 64/3 and the double integral of y over the region is 256/15. So y_avg = 4/5. Can you explain and show me how to do this ?