Crane Co. gathered the following information on power costs and factory machine usage for the last six months: Month Power Cost Factory Machine Hours January $29,440 16,300 February 37,546 22,400 March 33,920 19,200 April 27,260 15,600 May 24.940 14,000 June 21,700 11,000 Using the high-low method of analyzing costs, answer the following questions and show computations to support your answers. What is the estimated variable portion of power costs per factory machine hour? (Round answer to 2 decimal places, e.g. 15.25.) Variable power costs per factory machine hour