Predetermined Factory Overhead Rate 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: be shut down two weeks per year for general repairs. a. Determine the predetermined operating room overhead rate for the year. per hour b. Bill Harris had a 3-hour procedure on January 22 . How much operating room overhead would be charged to his procedure, using the rate determined in part (a)? 5 $