Jack Simpson, contract negotiator for Nebula Airframe Company, is currently involved in bidding on a follow-up government contract. In gathering cost data from the first three units, which Nebula produced under a research and development contract, he found that the first unit took 2,500 labor hours, the second took 1,750 labor hours, and the third took 1,650 hours. Use Exhibit 6.5. In a contract for three more units, how many labor hours should Simpson plan for?