yo how we calculated thats Fixed cost as given 4 but then next column 4.50 and 3.75??? how the number solved? please help me understand this problem

GIVEN VARIABLE COSTUNIT (prodlocow/cork writ) FIXED COSTS/UNIT dhe tale i produced 15 A (more mit fred cost decreases) 22,500 UNITS FIXED COSTS INCREASE BY 25% AT 23,000 UNITS REQUIRED /UNIT TOTAL TOTAL COST (PER/UNIT AND TOTAL) AT 25,000 UNITS VC FC 15.00 4.50 375.000 112.500 0.50 TOTAL 19.50 487.500 TOTAL COST FORMULA: 15 X 25,000 + 112,500 = 487,500 REQUIRED /UNIT TOTAL TOTAL COST (PER/UNIT AND TOTAL) AT 30,000 UNITS VC 15.00 3.75 450.000 112,500 FC 0.25 TOTAL 18.75 562.500 TOTAL COST FORMULA: 15 X 30,000 + 112,500 = 562.500