Sandhill Co. gathered the following information on power costs and factory machine usage for the last six months: Month Power Cost Factory Machine Hours January $28,810 16,000 February 36,7511 21,800 March 33,305 18,900 April 26,645 15,300 May 24.310 13,700 June 21,100 10,700 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