The quartic regression option finds the equation of a fourth degree polynomial of the form

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)}.

To view the statistics calculation options press .

Press find the quartic regression optiion -- polynomial of degree four, P4Reg.

Select P4Reg, .

Run quartic regression by pressing . Scroll to the right to see all of the coefficients.

Therefore, the best-fit quartic equation for this data is approximately y = .00011x

The TI-86 does not calculate the correlation coefficient r.