The manager of a direct mailing marketing firm wants to analyze whether, and if so how, the number of pieces of mail sent to households about a credit card promotion affects the number of credit card applications the firm receives. The manager collects data on the number of pieces of mail the firm has sent and number of applications received. Based on industry knowledge, the manager knows that customers do not necessarily apply for the credit card in the week they receive the mailing, but believes that some may apply in the week following the initial mailing. The manager wishes to perform a regression analysis using two independent variables: the number of pieces of mail sent during a specified week, and the number sent the week preceding the specified week. Create a new lagged variable in the highlighted column: "Pieces of Mail Sent the Preceding Week" to allow for the appropriate regression analysis.