Fitting a Quadratic in Microsoft® Excel

Chapter 4, Printout 2

Note: Excel's Data Analysis tools have no built-in routine for fitting a polynomial. This example shows how to fit a quadratic using Excel's multiple linear regression tool to find y as a function of x and x2.
  1. Enter the data.

  2. Find y as a function of x and x2 using multiple linear regression.

    Excel creates a new sheet in the workbook with the summary statistics, plots of residuals vs. x and x2, and a normal probability plot.

    Screenshot (summary output): screenshot

    Screenshot (plots): screenshot

    Note: you can move the charts as necessary by clicking a blank area in the chart and dragging it to a new location. Other changes can be made by double-clicking various elements in the charts.