clc, clear, close all;
x1 = -2.5;
y1 = -62;
x2 = -1.5;
y2 = -7.2;
x3 = -.5;
y3 = 8.3;
x4 = 1;
y4 = 3.7;
x5 = 3;
y5 = 45.7;

A=[x1;x2;x3;x4;x5];
B=[A.^4 A.^3 A.^2 A ];
K=[y1;y2;y3;y4;y5];
C=horzcat(B,[1;1;1;1;1],K);
D=rref(C);
F=D(:,6)
hold on;
plot(A,transpose(K),' o')
syms x
fplot((F(1)*x^4)+(F(2)*x^3)+(F(3)*x^2)+(F(4)*x)+F(5))