You have developed a new ergonomic pencil, called the ErgCil. From a survey, you learn that 500 people would be willing to pay $15 for an ErgCil, 1,000 people would be willing to pay $10 for such an ErgCil, and 1,500 people would be willin to pay $5. You want to make as much profit as possible. Therefore, you should produce 9 Gallon. A...\