Given the following cost and activity observations for Smithson Company's utilities, use the high-low method to determine Smithson's fixed costs per month. Round your final answer to the nearest dollar. Do not round interim calculations.

Cost Machine Hours

January $26,400 10,000

February 36,400 18,300

March 28,300 12,400

April 31,100 15,500

a.$45,926

b.$24,398

c.$14,352

d.$11,482