The controller of Wildhorse Production has collected the following monthly cost data for analyzing the behavior of electricity costs. Total Electricity Costs Total Machine Hours January $2,450 230 February 3,060 380 March 3,520 480 April 4,760 685 May 3,190 410 June 4,910 800 July 4,030 650 August 3,870 540 September 5,040 680 October 4,260 610 November 3,250 380 December 7,170 8201 What electricity cost does the cost equation estimate for a level of activity of 480 machine hours? Electricity cost $ By what amount does this differ from March's observed cost for 480 machine hours? Amount differ