A new online bookstore ships thousands of books to its customers each week. The director of this firm's shipping department is concerned about a seemingly large number of complaints from customers regarding errors in shipments. The managers of the organization know that the future profitability of this virtual bookstore depends essentially on its ability to fill customer orders quickly and accurately. In an effort to investigate this problem further, the shipping director collects data on the number of shipments not conforming to corresponding customer orders for 25 days in a row. The file P20_21.xlsx contains the number of reported nonconforming shipments out of the 75 shipments randomly selected on each of the 25 days. Do these data indicate a high average proportion of shipment errors? Is there an excessive amount of variability in the error rate of the company's shipments? If so, what can managers do in both the short run and the long run to improve the situation?