Can you help me with the MATLAB code?

I have been given the following information

I have found the values of a, b and c with MATLAB. I got the values (a, b, c) = (32.5, 25.5, 7.5) through the normal equation and least-squares fit on the data.

My question is: How do i calculate the absolute error below in MATLAB?

I am supposed to state it with two decimal places:

Answer 1

[KSSV]

LEt a, b, c be your coefficients and (x,y) be your data.

y0 =  y ;     % given data 
y1 = a+b*x+c*(x.^2-1) ;   % approximated data 
abs_error = sum(abs(y0-y1)) ;