Find the best fitting (smallest "Sum of squares of deviations:")
                                    line 
                                         f(x) = mx + b
         
           for the following two points using Data Flyer:

             -5 -1   <------ point a
              0  3   <------ point b

Now, REFRESH the Data Flyer application and try these three points:

            -5   -1           point a  (same as before)
             0    3           point b  (same as before)
            -2.5  2           point c  <----- this new 3rd point
 
     Can you get the Sum of squares of deviations: 0.67 or less????

     Note:  It is helpful to click on "Light Grid Lines" 

     When you get the 0.67 or less 
          for the Sum of the squares of the deviations, 
          after doing enough Change Function and Slider adjusting,

          you have discovered your 
             best fitting function 

          f(x) = mx + b, or

            y  =  mx + b    What is m?   What is b?

Know the idea 
     of the RISE                                                       
                 (the y2 - y1 or y difference 
                                        or distance or change)
    and 
        the RUN 
                 (the x difference, x2 - x2, 
                                      the x distance or change)

              E                     E              R
              S                    S               I
              I                   I                S
              R      or          R                 E
       R U N               R U N             R U N 

       Run across (the x-axis)    Rise UP (on the y-axis)

       Rise
      ------  =   slope of the line connecting the two points
       Run

       y = mx + b

           m is the SLOPE of the line

           b is the INTERCEPT for the line, i.e. when
         
                              x equals 0, where does the 
                                          line intercept the y axis.