Depends on whether the radius errors are generated from a separate process than the mass errors. (1) Get a glob of molten metal, mass determined by how much met

Depends on whether the radius errors are generated from a separate process than the mass errors. (1) Get a glob of molten metal, mass determined by how much metal is there, some error there; (2) shape it into a ball, and suppose the radius is mainly determined by air that gets trapped, then some nearly independent error there.