A manufacturer produces two models of elliptical cross-training exercise machines. The times for assembling, finishing, and packaging model X are 3 hours, 3 hours, and 0.8 hour, respectively. The times for model Y are 4 hours, 2.5 hours, and 0.4 hour. The total times available for assembling, finishing, and packaging are 9000 hours, 6300 hours, and 1350 hours, respectively. The profits per unit are $300 for model X and $375 for model Y. What is the optimal production level for each model?