Head calibration data:

              
            

            

              
Head data to back predict:

              

              
            

          

        

      

      
      
      

        

          
          

            

              
            

            

              
            

            

              
            

            

              
            

            

              
            

            

              
            

            

              
            

            

              
            

            

              
            

            

              
            

            

              
            

            

              
            

            

              
            

            

              
            

          

        

      

      

        

        

          Linear regression:
        

        

          
        

        
        

        

      

      

        

        

          Weighted (1/X) linear regression:
        

        

          
        

        
        

        

      

      

        

        

          Weighted (1/X^2) linear regression:
        

        

          
        

        
        

        

      

      

        

        

          Linear regression after (base 10) LOGARITHM transformation of both concentration and response:
        

        

          
        

        
        

        

      

      

        

        

          Linear regression after SQUARE ROOT transformation of both concentration and response:
        

        

          
        

        
        

        

      

      

        

        

          Quadratic regression:
        

        

          
        

        
        

        

      

      

        

        

          Weighted (1/X) quadratic regression:
        

        

          
        

        
        

        

      

      

        

        

          Weighted (1/X^2) quadratic regression:
        

        

          
        

        
        

        

      

      

        

        

          Four parameters logistic Regression:
        

        

          
        

        
        

        

      

      

        

        

          Weighted (POM) Four parameters logistic Regression:
        

        

          
        

        
        

        

      

      

        

        

          Five parameters logistic Regression:
        

        

          
        

        
        

        

      

      

        

        

          Weighted (POM) Five parameters logistic Regression:
        

        

          
        

        
        

        

      

      

        

        

          Power Regression:
        

        

          
        

        
        

        

      

      

        

        

          Weighted (POM) Power Regression: