LetC(x) be the natural cubic spline that interpolates the data. Describe whatC(x) consists of, and what conditions it has to satisfy. In particular, set up thesystem of linear equations (3.4.5) (in text book, 2nd edition) or (3.4.12) (in textbook, 1st edition). Find the spline functionC(x), and compute the value forC(1.8). The computation here can be time consuming, and you may use Matlabto solve the system of linear equations.