Kohler manufacturing typically achieves one of three production levels in any given year: 8 million pounds of steel, 10 million pounds of steel, or 16 million pounds of steel. in tracking some of its costs, kohler's controller discovered one cost that was $10 per pound at a production level of 8 million pounds, $8 per pound at a production level of 10 million pounds, and $5 per pound at a production level of 16 million pounds. this is an example of a