Scatter Plot Template in Excel
Scatter plots are used to evaluate the correlation or cause-effect relationship (if any) between two variables (e.g., speed and gas consumption in a vehicle).
When you think there's a cause-effect link between two indicators (e.g., calories consumed and weight gain) then you can use the scatter plot to prove or disprove it. If the points are tightly clustered along the trend line, then there's probably a strong correlation. If it looks more like a shotgun blast, there is no correlation.
Here is an example of a scatter plot template created using the QI Macros SPC Software.