presented below is the production data for six months of the year showing the mixed cost incurred by columbia company. month cost unit july $7,500 4,000 august 10,250 6,500 september 10,500 8,000 october 12,700 10,500 november 13,500 12,000 december 10,850 9,000 columbia company uses the high-low method to analyze mixed costs. the total fixed cost is _____: A)$4,000 B)$10,500 C)$10,417 D)$4,500