how can i get 4.5

GIVEN: VARIABLE COST/UNIT FIXED COSTS/UNIT UNITS 15 4 22,500 FIXED COSTS INCREASE BY 25% AT 23,000 UNITS REQUIRED: TOTAL COST (PER/UNIT AND TOTAL) AT 25,000 UNITS VC FC TOTAL UNIT 15.00 4.50 19.50 TOTAL 375,000 112,500 487,500 TOTAL COST FORMULA: 15 X 25,000 + 112,500 = 487,500 REQUIRED: TOTAL COST (PER/UNIT AND TOTAL) AT 30,000 UNITS VC FC TOTAL /UNIT 15.00 3.75 18.75 TOTAL 450,000 112,500 562,500 TOTAL COST FORMULA: 15 X 30,000 + 112,500 = 562,500