28. Parasol Systems sells motherboards for personal computers. They use the following model to price their products: for quantities up to 30, the company charges $325.00; for quantities betweern 30 and 50 they charge $300.00 for each board beyond 30; and they charge $275.00 per board for quantities beyond 50. A given table presents the last orders for motherboards. Calculate the total revenues. (Refer to worksheet "4.28".)