Quantitative variables take the form of numerical figures. Qualitative variables describe data by placing them into broad categories. For example, the number of units that your business sells over a ...

A two-valued qualitative variable can be represented by a single 0-or-1-valued "dummy" variable. If a qualitative variable has three or more possible values (e.g., make-of-car, or marital-status), ...

The standard linear regression model does not apply when the effect of one explanatory variable on the dependent variable depends on the value of another explanatory variable. In this case, the ...

Jim Chappelow is an independent consulting economist with over 13 years of experience in economic development, research, teaching, forecasting, and consulting. David Kindness is a Certified Public ...