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.

How Excel Charts Work A chart has an x-axis range and a y-axis range to show the correlation between two different data sets. The x-axis is the horizontal category line.

If you have uneven distribution of data in your Excel chart, here is a better way to change the automatic axis settings.

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.

Revise how to plot a linear equation graph. Learn how to read x and y coordinates from a graph in this BBC Bitesize maths KS3 guide.