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 $179,300 Depreciation expense 32,300 Utilities 18,800 269,300 Nurse salaries Technician wages 88,300 Total operating room overhead $588,000