Use the regression model of Data Analysis for the data. If the log$-$linear regression should be used, prepare the data before adding the regression model.

Preparing Data $($if the log$-$linear regression should be used$)$

Go to the Data worksheet. In cell C$1,$ type LN Price. In cell D$1,$ type LN Quantity.

In cell C$2,$ by using a cell reference, calculate LN of the Retum Price in cell A$2.$ Copy the formula from cell C$2$ down the column to cell C$21.$ Use the Excel LN function.

In cell D$2,$ by using a cell reference, calculate LN of the Return Completed in cell B$2.$ Copy the formula from cell D$2$ down the column to cell D$21.$ Use the Excel LN function.

$6$ Adding Regression Model

Go to the Data worksheet if you are not already there. Select the Data Analysis in the Analyze group of the Data tab of the Ribbon $($note you should add this Add$-$in in case you do not have it in the Data tab already$).$ Select Regression and click OK$.$ Select the cells in the Retums Completed column as the Input $Y$ Range and the cells in the Return Price column as the Input $x$ Range if the linear regression should be used. Select the cells in the LN Quantity column as the Input $Y$ Range and the cells in the LN Price column as the Input X Range if the log$-$linear regression should be used. Choose cell F$1$ on the Data worksheet as the output range. Do not check any additional boxes in the regression model menu.

On the Problem worksheet, in cells D$9$ and H$9,$ determine the correct variables to be used in the least squares regression equation. In cells E$9$ and G$9,$ enter the values of the coefficients to write the least square regression equation in the proper form. Use cell references to the