Making Graphs in Excel

Making/Changing a Graph

• Select all the cells that contain the data that you want to graph.
• Click on the Chart Wizard icon. You will see a series of dialog boxes.
• Screen 1: Choose "XY (Scatter)" and click "Next."
• Screen 2: This screen allows you to choose which data to plot. Since you did this before starting the Wizard, just click "Next."
• Screen 3: This screen has multiple menus. Play with the settings to see what they do. Make sure your final graph has a title, axes that are labeled (with units), and no legend. When you are done, click "Next"
• Screen 4: This screen selects where you will store the graph. Choose "As object in" to store the graph in the same worksheet as the data and click"Finish"





• Once the graph is made, you can modify most features of the graph by double-clicking on the feature you want to change. You can also right-click on a feature to get a menu. Try changing the color of the plot area, the numbers on the axes and the appearance of the data points.

Adding Error Bars

Right-click on a data point and choose "Format data series..." Click on the "Y error bars" tab. Choose "Both" under "Display" and "Fixed Value" under "Error Amount". Then enter the uncertainty for the y-values in the box marked "Fixed Value."

Adding a Trendline

Sometimes you want to find (and interpret) the equation that relates the two variables you graphed. To make a trendline and determine its equation, right-click on a data point and choose "Add trendline." Choose the shape that best describes your graph. Click on the "Options" tab. Check the box for "Display equation on chart" Use the simplest equation that you think will cut through all the error bars on your graph. You may need to try a couple of trendlines before you get the most appopriate one. To clear a trendline, right-click on the trendline and select "Clear".

Warning: It is very easy to use the trendline tools to produce nonsense. The purpose of his tool is to find the simplest mathematical model that explains the relationship between the two variables you are graphing. Look at the equation and shape of the trendline critically: Do they make sense? Is this the simplest possible explanation for the relationship between the two variables?