The Fuller Company has provided the following information Month Direct Labour Hours Factory Overhead July 23,000 $460,475 August 26,400 $565,280 September 18,800 $419,010 October 21,600 $447,970 November 28,600 $543,470 December 19.400 $437,020 Fuller Company uses the high-low method to analyze mixed costs. The cost function would be stated as: a.y = 180,250 + 19.24x b.y = 180,250 +12.70x c. y = 57,184 + 19.24x d. y = 128,260 + 12.70x