**Be Careful with Universal Formulas**
claudio pizzi, Business Consultant, Argentina, Member

I advise you to be very careful with the application of these relationships. These formulas were designed for a group of companies, a statistical sample. The secret is in the formula variables (0.01, 0.02, 0, xx, etc.) used to multiply the coefficients. The coefficients (ratios) used to construct the formulas might be right (perfect statistical correlation between them), the problem is the calibration appears. You need to use a statistical program to adjust those numbers (0.01 - 0.02, etc) in its customer base.