Linear Regression
The linear regression option finds the equation of a linear equation of
the form y = a + bx that best fits a set of data.
First, press 
to
enter the data .
The data shown here is the points {(2,11.4) (3,17) (5,27.3) (7,36.1) (11,47.7) (13,49.9)}.
Press 
to view the statistics calculation options.
Press 
.
Therefore, the best-fit linear equation for this data is approximately y = 7.42 + 3.53x.
Note: The resulting linear equation is an exact fit if two nonvertical data points
are entered.
The TI-86 calculates the correlation coefficient, r, as corr.
The coefficient of determination, r2 is found in the catalog.