How to Graph a Quadratic Regression

Using an Applet

• 1

  Access the quadratic regression applet.

• 2

  Input data for the independent variable in the first column. Enter data for the dependent, complementing values in the second column. Rename the columns for your convenience.

• 3

  Click on the "Plot" button and a quadratic function will appear.

• 4

  Click on "Analyze" to graph a quadratic regression line. Observe the equation of the regression function as well as the percentage error and correlation coefficient.

• 5

  Click on the numerical tab between "Results" and "Precision" to denote the decimal place of your results.

• 6

  Press "Clear" to graph another quadratic regression.

Using a Software Spreadsheet

• 7

  Click on "New" to create a new spreadsheet in a statistics program such as Microsoft Excel.

• 8

  Input the independent variable data points in the first column. Insert the data points of the dependent variable in the second column.

• 9

  Highlight both columns and select the "Chart Wizard" button.

• 10

  Select the "XY (Scatter) Plot." Choose the "Only True Sub-Type" scatter plot.

• 11

  Click on "Next," "Finish". View your graph and modify its font, color and background, if necessary.

• 12

  Right-click on the graph, click on "Chart" and drag down to "Add Trendline."

• 13

  Choose "quadratic" under the "Type" tab and select "Display equation on chart" under the "Options" tab. View the results of your quadratic regression analysis.