The graph shows the relationship between the precipitation and the streamflow. The streamflow increases with precipitation, but not always in the same relationship. These variations or factors could be accounted for by either vegetation, land saturation, runoff due to melting, or solidity of the ground (i.e. the ground is frozen).

I can see myself using Excel to analyze physical properties of materials with students. We can enter mass and volume, calculate density. Graph the change in density with volume of similar substances or compare the density of several solids or liquids.