Below is a video with instructions on how to create a scatter plot on Excel (it works the same way for Excel 2010 and 2013) with more than one set of data on the graph. These instructions are perfect for making your graphs for the Cemetery lab write up. It is best to put data that you plan to compare on the same set of axes. It makes comparison so much easier.
You should also add a best fit line by choosing linear from the trend line options instead of polynomial as the man did in this video. Be sure to check the intercept box and have the intercept be 0.0 so that the trend line will go through the origin.