3. A stamping plant must be designed to supply an automotive engine plant with sheet metal stampings. The plant will operate one 8 hour shift for 250 days per year and must produce 15,000,000 good quality stampings annually. Batch size = 10,000 good stampings produced per batch. Scrap rate = 5%. On average it takes 3.0 seconds to produce each stamping when the presses are running. Before each batch, the press must be set up, and it takes 4 hours to accomplish each setup. Presses are 90% reliable during production and 100% reliable during setup. How many stamping presses will be required to accomplish the specified production?