A standing inspector picks up 25 lb castings from a conveyor 50 inches from the floor with a horizontal distance of 20 inches. He then puts the casting on a work area 20 inches lower than the conveyor and closer to the body (a minimum horizontal distance) for inspection. For good ones, he twists 90? to the right and sets it on another conveyor 30 inches from the floor with a minimum horizontal distance. For bad ones, he twists 90? To the left and sets it on a third conveyor 30 inches from the floor with a minimum horizontal distance. How many casting per minute can he inspect for an 8-hour shift so as to be acceptable according to NIOSH guidelines? Redesign the job, at minimal cost (i.e. no costly robotics or automation), so as to be able to double production but still keep back strain to acceptable levels.