Find the average value of the function over the given solid. the average value of a continuous function f(x, y, z) over a solid region q is 1 v q f(x, y, z) dv where v is the volume of the solid region q. f(x, y, z) = x + y + z over the tetrahedron in the first octant with vertices (0, 0, 0), (2, 0, 0), (0, 2, 0) and (0, 0, 2).