Suppose you have created some kind of graph with a data series and you want to add a second data series to the graph. In the Excel sheet below, we have a scatter plot of the data in cells A1 through B4.
We want to add the data in cells A8 through B18 to this graph.
This will open the Select Data Source box. You can see that this graph already has a data series named Series1 on it. To add another data series, choose Add.
The Edit Series allows you to enter the cells in which your data series resides. Move the cursor to the Series X values box. Now drag select the data that you want to be graphed horizontally. Move the cursor to the Series Y values box and delete any entries there. Drag select the data that you want to graphed vertically.
Click OK twice. The new scatter plot shows the first data series in blue and the second data series in orange. For these scatter plots there is some overlap so not all of the blue points are visible.