To add the r square value to the graph click the Display R-squared value on chart check box. Instead of a formula enter your target values in the last column and insert the Clustered Column - Line combo chart as shown in this example. Select the chart area of a chart click in the Formula Bar or not Excel will assume youre typing a SERIES formula and start typing.
That adds r squared to the graph just below the equation as in the snapshot below.
You can drag the equation and correlation box to alter its position on the scatter plot. We will tabulate our data in two columns. The equation will be in the form of y mx b where m and b will be numbers. In cell B2 type y.