Aurora Muffler, Inc. operates an automobile service facility. The table below shows the cost incurred during a month when 500 mufflers were replaced. Number of Muffler Replacements 400 500 600 Total costs: Fixed costs $ 9,000 Variable costs 6,000 Total costs $15.000 Cost per muffler replacement: Fixed cost Variable cost Total cost per muffler replacement ZAI Required: Fill in the missing amounts, labeled A through O, in the table above