Introduction

A very common exercise when analyzing data is fitting a curve through that data. Curve fitting is the process of trying to find the curve (which is represented by some model equation) that best represents the sample data, or more specifically the relationship between the independent and dependent variables in the dataset. When the results of the curve fit are to be used for making new predictions of the dependent variable, this process is known as regression. Sometimes, you may want to fit a curve just to interpolate a set of data. At other times, you may actually want to extrapolate beyond the sample data. In still other cases, curve fitting can be used to predict parameters of some known model (an equation) given a set of observed data. In this chapter, I discuss several different techniques for performing linear and nonlinear curve fitting in Excel.