Predetermined factory overhead rate 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 the operating room will be shut down two weeks per year for general repairs. This information has been collected in the Microsoft Excel Online file. Open the spreadsheet, perform the required analysis, and input your answers in the questions below. Open spreadsheet a. Determine the predetermined operating room overhead rate for the year. Round your answer to the nearest dollar. per hour 9 your answer as a positive number. Round your answer to the nearest dollar. $