The equation that describes how the dependent variable (y) is related to the independent variable (x) is called the regression model. This equation is a result from the statistical modeling called the regression analysis. It is a method used to estimate relationships of a response variable and predictor variables being measured. The simplest type of regression is the linear regression where the relation ship between the independent variable x and the dependent variable y is being predicted. These equations can be used to predict values that are beyond the measuring values of the experiment. Also, these are used to describe the behavior of the variables.