The controller of Sheridan Production has collected the following monthly cost data for analyzing the behavior of electricity costs. Total Electricity Costs Total Machine Hours January $2,380 200 February 3,010 390 March 3,600 490 April 4,800 690 May 3,150 500 June 4,900 710 July 4,040 645 August 3,880 530 September 5,060 675 October 4,200 610 November 3,390 390