HOW TO USE THE EXCEL CHART WIZARD FOR GRAPHING AND ANALYZING DATA
1. Organize your data properly in columns. The X-data (i.e. the horizontal axis data) should be placed in a column to the left of the column of Y-data (i.e. the vertical axis data). Column headers with variable names and units may be placed at the top of each column to denote what variable is being plotted. 2. Highlight the data. The computer will always take the highlighted column farthest to the left to be the X-data. If your X-data is to the right of your Y-data, you will have to move the columns around before graphing 3. Click on the ChartWizard icon located on the tool bar in the top right part of the screen. You will then be prompted to do the following: a) Choose the general type of graph you want. In general, you will probably wish to choose an XY scatter graph, then select the first one (it has points unconnected by any lines). b) Indicate the method by which ChartWizard should interpret your data table. If your data series are in columns, you need only hit Return at this stage. c) Enter any text you may wish for your graph. At this stage, you may enter a graph title and axis labels. When you present a graph it is good to have a descriptive title, and good axis labels showing what is on the axis and the units. d) Chart Location- just Finish the job and obtain the graph on the screen.
4. Add a best-fit curve to your data. • Click on the data points on the chart. They should appear highlighted in some manner. • Click on the “Chart” menu and choose “Add Trendline”. • Choose whatever type of fit you would like (do you think the fit looks linear, parabolic…?) • Next click on the options tab at the top of the Add Trendline window. § Select the “Display equation on chart” option, and the “Display R_squared value on chart” option. This will display the equation of the best- fit function right on the graph, along with a measure of how well the function fits the data. • Click “OK” and Excel will do the rest. NOTE: The closer that R2 is to 1, the better your chosen function actually fits the data.