Toolbox is the most convenient.

Enter data first.

Open start-> Toolbox-> Curve fitting->; Curve fitting toolbox

Point data, select the two sets of numbers x and y you entered, and then click to create the data set and close it.

Point fitting->; New fit

There are many fitting methods for fitting types, and polynomial fitting is the default method.

Select 6th degree to fit 6th degree polynomial.

Point application

The fitting description appears in the box below, and the coefficients of all levels of the sixth polynomial are given.

Other fitting methods can also be used.

If we know the approximate range of the coefficient, we can determine this range.