Sanderson's Pipe produces plumbing pipe. The long-run total cost of Sanderson's is LTC = 20,000Q - 2000- Q' where is measured as thousands of feet of piping. The long-run marginal cost is LMC = 20,000 - 4000 30 a. Divide total cost by l to obtain the long-run average cost of producing pipe. Make sure ot use Q and not q when writing your function. Average cost = $