Grid lines add horizontal and/or vertical lines to your graph that aid in measuring graph values. By default, these grid lines use the color assigned to the "automatic" selection feature ...

When you create a graph in Excel ... sizes the X and Y axis lines, so the data you want to display is shown. You can override the settings and set the vertical and horizontal axis to the same ...

In order to work with gradients and straight lines successfully, a good understanding of coordinates and linear graphs ... by the change in \(x\), or the vertical divided by the horizontal.