Redfern Audio produces audio equipment including headphones. At the Campus Facility, it produces two wireless models, Standard and Enhanced, which differ both in the materials and components used and in the labor skill required. Data for the Campus Plant for the third quarter follow. Standard Enhanced Total Units produced 24,000 8,000 32,000 Machine-hours 14,400 9,600 24,000 Direct labor-hours 18,000 18,000 36,000 Direct materials costs $ 480,000 $ 720,000 $ 1,200,000 Direct labor costs 288,000 612,000 900,000 Manufacturing overhead 864,000 Total costs $ 2,964,000

Required: Compute the predetermined overhead rate assuming that Redfern Audio uses direct material costs to allocate overhead costs.