How to Add a Second Y-Axis on Excel & Make a Second Series at the End of the Chart. Microsoft Excel charts give you a large number of options for displaying the data in your spreadsheet.

Excel automatically distributes these points along a uniform X axis. To add more data to the Y axis in a line chart, add additional numbers in cells below your existing data.

In Microsoft Excel, to draw attention to a specific marker in a line chart, drop in a thin line, think of it as a marker.