How to Find the Slope of a Line on an Excel Graph. In math and statistics, you may occasionally need to calculate the slope of a line generated by coordinates in the (x,y) format.

For example, you could show line graphs for temperature and humidity on top of each other. For this purpose, Excel lets you add a series of data to a chart and plot it on a second y-axis.

We discuss a comment on a previous post stating that the text of labels on the vertical axis of graphs must be horizontal by discussing the pros and cons of four possible positions for these labels.

Learn about line graphs with this BBC Bitesize Maths article. For students between the ages of 11 and 14.