Given the following cost and activity observations for Smithson Company's utilities, use the high-low method to calculate Smithson's fixed costs per month. Round your final answer to the nearest dollar. Do not round interim calculations. Cost Machine Hours January February $26,400 35,200 28,400 30,200 10,500 17,500 12,200 March April 14,900 Oa. $42,240 Ob. $10,560 O c. $13,200 Od. $22,440