The following information is available for a company's utility cost for operating its machines over the last four months. Month January February March April Machine hours 940 1,840 2,480 640 Utility cost $5,490 $6,980 $8,100 $3,900 Using the high-low method, the estimated variable cost per unit for utilities is: Multiple Choice O O $5.30 o $4.15, O O $6.09. 0 $2.28 O $3.27