Yates Corp. wants to develop a cost equation for its administrative costs. The controller believes the appropriate cost driver is units produced. Last year's data are presented below: Administrative Units Month Produced Costs $ 24,288 27,720 32,500 January February 37,700 March 24,700 17,820 April 40,300 30,360 49,400 37,290 May June 42,900 29,040 July August September 53,300 32,670 45,500 30,030 26,000 20,460 October 48,100 34,320 November 61,100 40,920 December 54,600 36,630 Total 516,100 $361,548 Average 43,008 $30,129 Required: (a.) What is the equation for administrative costs using the high-low method? (b.) Prepare an estimate of administrative costs for a month when 30,000 units are produced