4.The cost of producing and selling a certain item is $220x $115,000 for the first 1,000 units, $120x $115,000 for a production range between 1,000 and 2,500 units, and $205x - $97,500 for more than 2,500 units, where x is the number of units produced. If the selling price is $200 per unit, and all units produced are sold, find the level of production that will maximize profit