Safeguard produces metal doors for households and businesses. The company makes three different door models. The company uses the same machinery to produce the three door models. The machinery can run for 4,002 hours per period. Sales prices, variable costs and other relevant information are as follows: Requirements 1. Is the machinery considered a constraint resource? Why? 2. Compute the contribution margin per hour of machine time. 3. Which product should Safeguard emphasize? Why? 4. To maximize profits, how many doors of each model should Safeguard produce? 5. Given this product mix, what will the company's total contribution margin be