Rockwood Manufacturing typically achieves one of three production levels in any given year: 6 million pounds of steel, 10 million pounds of steel, or 15 million pounds of steel. In tracking some of its costs, Rockwood's controller discovered one cost that was $10 per pound at a production level of 6 million pounds, $6 per pound at a production level of 10 million pounds, and $4 per pound at a production level of 15 million pounds. This is an example of a

Selected Answer: variable cost.

Answers: semifixed cost.

variable cost.

fixed cost.

semivariable cost.