Overview
This tutorial explains how to add a trendline, display its equation, and show the R-squared value on a scatter plot in Microsoft Excel.
Creating a Scatter Plot
- Highlight your data, including variable labels, in Excel.
- Go to the Insert tab and choose a basic scatter plot to display your data.
Adding a Trendline
- With the scatter plot selected, use Chart Design > Add Chart Element > Trendline and select Linear.
- Alternatively, right-click data points and choose Add Trendline, or use the plus icon near the chart and select Trendline.
- Customize the trendline’s appearance (color, thickness, style) using the Format tab and Shape Outline option.
Displaying the Line Equation
- Right-click the trendline and select Format Trendline to open a sidebar.
- Check the box for "Display equation on chart" to show the formula on the graph.
- Move and format the equation text box as needed (e.g., bold, change font size under Home tab).
Showing the R-squared Value
- In the Format Trendline sidebar, check "Display R-squared value on chart."
- The R-squared value will appear on the graph, usually below the equation.
Key Terms & Definitions
- Scatter Plot — a graph displaying points representing paired values of two variables.
- Trendline — a line showing the general direction or relationship in scatter plot data.
- Linear Trendline — a straight line best fitting the data, used for linear relationships.
- Equation of the Line — mathematical formula (y = mx + c) representing the trendline.
- R-squared Value — statistical measure indicating how well data fit the trendline (ranges from 0 to 1).
Action Items / Next Steps
- Practice adding a trendline, equation, and R-squared value to your own Excel scatter plot.
- Review further materials on linear regression for deeper understanding of the equation and R-squared.