That is the the basic form of linear regression by hand. Note that there ARE other ways to do this - more complicated ways (assuming different types of distributions for the data).

F. Baldassari, B. Dwork, On Second Order Linear Differential Equations with Algebraic Solutions, American Journal of Mathematics, Vol. 101, No. 1 (Feb., 1979), pp. 42-76 ...

In the present paper the authors propose an algorithmic procedure different from the known algorithms [1,2] of searching for the Liouvillian solutions of linear ordinary differential equations (LODE) ...