January 1 of the current year, the annual operating room overhead is estimated to be: \begin{tabular}{lr} Disposable supplies & $247,900 \\ Depreciation expense & 62,100 \\ Utilities & 26,500 \\ Nurse salaries & 230,500 \\ Technician wages & 105,000 \\ Total operating room overhead & $672,000 \\ \hline \end{tabular} 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. x Open spreadsheet a. Determine the predetermined operating room overhead rate for the year. Round your answer to the nearest dollar. per hour