17 Northridge, Inc., uses the high-low method to analyze cost behavior. The company observed that at 20,000 machine hours of activity, total maintenance costs averaged $10.50 per hour. When activity jumped to 24,000 machine hours, which was still within the relevant range, the average total cost per machine hour was $9.75. On the basis of this information, the company's fixed * .maintenance costs were (2 (2 )