CC, Inc., provides billing services for the health care industry. To ensure that its processes are operating as intended, CC selects 100 billing records at random every day and inspects each record to determine if it is free of errors. A billing record is classified as defective whenever there is an error that requires that the bill be reprocessed and mailed again. Such errors can occur for a variety of reasons. For example, a defective bill could have an incorrect mailing address, a wrong insurance identification number, or an improper doctor or hospital reference. The sample data taken from the most recent five weeks of billing records are contained in the file CC Inc.

Use the sample information to construct the appropriate 3-sigma control chart. Does CC’s billing process appear to be in control? What, if any, comments can you make regarding the performance of its billing process?