Global Publishers has collected the following data for recent months: Month Issues published Total cost March 20,500 $20,960 22,464 April 21,800 May 18,495 17,750 21,200 June 21,395 Required: a. Using the high-low method, find variable cost per unit, total fixed costs, and the total cost equation. Round the variable cost to two decimal places. Variable cost per unit per unit Total fixed costs Total cost = $ + ($ x Number of issues published) b. What is the estimated cost for a month in which 19,000 issues are published