CT-Scan Palace received some complaints from the physicians that it takes radiologists too long to provide CT-scan results, which prevents physicians from providing the appropriate treatments in a timely manner. The Quality Team at Reliable CT-Scan Palace decided to gather data on turnaround times and inserted the weekly average turnaround times over 35 weeks in an Excel file to investigate whether there is special cause variation or common cause variation in the delivery of CT scan results. Use the appropriate SPC chart to explore whether the CT-scan system is in control or not and draw conclusion.