Write Yes if the statement is proportion and No if it is not. Write your answer on the blank. 1) 6 : 9 = 2 : 3 3) 5 : 3 = 32 : 24 5) 4 : 5 = 9 : 1 2) 7 : 4 = 14 : 8 4) 30 : 10 = 18 : 6

Use stokes' theorem to evaluate c f · dr where c is oriented counterclockwise as viewed from above. f(x, y, z) = xyi + 5zj + 7yk, c is the curve of intersection of the plane x + z = 8 and the cylinder x2 + y2 = 81.