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 to Add a Legend to a Scatter Plot in Excel. The legend on an Excel scatter plot is simply a list of the names for each of the series on the chart.

Want to know how to create a scatter plot in Excel? Here's a guide on how we created a simple chart based on performance numbers.