Predetermined Factory Overhead Rate Poehling Medical Center has a single operating room that is used by local physicians to perform surgical procedures. The cost of using the operating room is accumulated by each patient procedure and includes the direct materials costs (drugs and medical devices), physician surgical time, and operating room overhead. On January 1 of the current year, the annual operating room overhead is estimated to be: Disposable supplies $170,800 Depreciation expense Utilities 30,800 17,900 Nurse salaries 256,500 Technician wages 84,000 Total operating room overhead $560,000 of surgical room hours. Poehling Medical Center expects to use the operating room an average of eight