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.

	Cost	Machine Hours
January	$90,350	10,500
February	146,600	18,000
March	103,450	12,200
April	123,580	14,900

a.$19,700

b.$9,300

c.$37,100

d.$11,600