6-16
k Displaying Regression Calculation Results
  Whenever you perform a regression calculation, the  regression formula parameter (such 
as  a  and  b  in the linear regression  y  =  ax  +  b ) calculation results appear on the display. The 
regression formula parameter calculation results also appear as soon as you press 1(CALC) 
and then a function key to select a regression type, while a graph is on the display.  
  The following parameters will also appear on the regression calculation result screen.
  
   r   ..............correlation coefficient (linear regression, logarithmic regression, exponential 
regression, and power regression only)
   r  
2 
 .............coefficient of determination (except for Med-Med, sinusoidal regression, and 
logistic regression)
   MSe .........mean square error (except for Med-Med)
k Graphing Statistical Calculation Results
  While the parameter calculation result is on the display, you can graph the displayed 
regression formula by pressing  6(DRAW).
k Linear Regression Graph
  Linear regression uses the method of least squares to plot a straight line that passes close to 
as many data points as possible, and returns values for the slope and  y -intercept ( y -coordinate 
when  x  = 0) of the line.
  The graphic representation of this relationship is a linear regression graph.
  
        1(CALC) 2(X) 
        1( 
ax + b ) or  2( a + bx )
        6(DRAW)
  
  The following is the linear regression model formula.
   y   =  ax  +  b 
   a  
 .............regression coefficient (slope)
   b   .............regression constant term ( y -intercept)
  
   y   =  a  +  bx 
   a  
 .............regression constant term ( y -intercept)
   b   .............regression coefficient (slope)