The extrusion die for a polyethylene parison used in blow molding has a mean diameter of 18.0 mm. The size of the ring opening in the die is 2.0 mm. The mean diameter of the parison is observed to swell to a size of 21 5 mm after exiting the die orifice. If the diameter of the blow molded container is to be 150 mm, determine
(a) the corresponding wall thickness of the container, and
(b) the wall thickness of the parison.