linear regression

X = 1:6;
Y = [1 22 50 62 97 110];
plot(X,Y,'o');
hold on;
a = polyfit(X,Y,1);
Y_H = polyval(a,X);
plot(X, Y_H);
legend('observed', 'predicted');
xlabel('predictor');
ylabel('respond variable');
E = Y_H - Y;
MSE = sqrt(mean(E.^2));
display(MSE);