A manufacturer was not satisfied with the irregular cycle time and production level in the manual production of plastic garbage cans with an injection molding machine. The efficiency of the machine operators varied during the 8-hour shift. The operator ran a part every 45 seconds for the first 2 hours of a shift, ran a part every 50 seconds for the middle 4 hours of the shift, and ran a part every 60 seconds for the last 2 hours of the shift. The efficiency level was essentially the same during all three shifts. The manufacturer used a robot and achieved a consistent 48-second cycle time for all three shifts. Determine the payback period in days of 3-shift production to justify the $218,400 robot system cost, using a savings of $200 per shift for elimination of an operator and $10 per additional can produced by the robot (over manual production level).