Pharoah Co. gathered the following information on power costs and factory machine usage for the last six months: Month Factory Machine Hours Power Cost $25,660 January 14,500 February 32.212 18,800 March 30.230 17,400 April 23,570 13.800 May 21,160 12,200 June 18,100 9,200 Using the high-low method of analyzing costs, answer the following questions and show computations to support your answers. (a) What is the estimated variable portion of power costs per factory machine hour? (Round answer to 2 decimal places, eg. 15.25.) Variable power costs per factory machine hour