Quartic Regression
The quartic regression option finds the equation of
the form y = ax4 + bx3 + cx2 + dx + e
that best fits a set of data.
First, enter the data.
The data shown here are 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 
for regressions, then
to select quartic.
Therefore, the best-fit quartic equation for this data is approximately
y = .00011x4 - .0104x3 - .0504x2 + 6.037x - 3.89.
(Note the scientific notation for the first term.)
Note: The resulting quartic equation is an exact fit if five noncollinear, nonparabolic,
noncubic data points are entered.
The correlation coefficient r is not calculated.
If an error message occurs, make
sure the data was entered correctly or press
to view the setup.
Use 
, 
,
and the menu keys to select List1 for 2Var XList,
List2 for 2Var YList,
and 1 for 2Var Freq.