Assume that a company wants to separate a mixed cost into its variable and fixed elements for cost estimation purposes. It provided the following information: Month Units Produced Mixed Cost January 1,050 $ 11,045 February 1,150 $ 11,870 March 1,100 $ 11,560 April 1,250 $ 12,100 May 950 $ 10,800 June 1,280 $ 12,210 July 990 $ 10,970 August 1,010 $ 11,005 The regression equation used for estimating the total mixed cost for a given level of activity is closest to