%Highlight lines 4-8 of the code and evaluate
%the selection. This file and regress.mat 
%must be in the same folder location
clf
X=xlsread('data.xls');
N=length(X);
j=4*(0:N)/N;
plot(X(1,:),X(2,:),'r*')
%%%%%%%%%%%
A=[ ones(1,N); X(1,:); X(1,:).^2];
Y=A*X(2,:)'
%Find  B(1) B(2) and B(3) for this 
%quadratic regression  and use it 
%to plot as coded below

hold on
l=B(1)+B(2)*j+B(3)*j.^2;
plot(j,l)
%print out your plot and write the numbers 
%B(1), B(2) b(3) on the plot. A screen shot or 
% something similar is also fine