Please show algebra/how you worked each step out if possible.

11. The following data was obtained from historical data: Month Volume April 700 May 900 June 760 July 400 August 820 September 880 October 550 November 650 Cost 20,800 22,000 21,000 18,100 21,200 21,600 19,400 20,200 a. Calculate an estimate of fixed costs using the high-low method