A team in an accounting group has been working on improving the processing of invoices. The team is trying to reduce the cost of processing invoices by decreasing the fraction of invoices with errors. The team developed the following operational definition for a defective invoice: an invoice is defective if it has an incorrect price, incorrect quantity, incorrect coding, incorrect address, or incorrect name. The team decided to pull a random number of invoices per day. If the invoice had one or more errors, it was defective. The data from the last 25 days are given in the table below. Construct a process control chart using the data given in the table. Is the process in control or out of control? Explain your answer. Day Number of Invoices Reviewed Number of Invoices with Errors 1 98 12 2 120 14 3 105 12 4 130 6 5 100 7 6 98 8 7 77 10 8 122 9 9 100 12 10 98 2 11 116 14 12 110 18 13 92 30 14 98 13 15 162 14 16 87 12 17 105 11 18 110 8 19 98 9 20 96 17 21 100 18 22 100 22 23 97 25 24 102 28 25 98 18