Y=[89.58, 86.3, 86.08, 83.8, 82.04, 81.06, 81; 80.76, 79.58, 79.14, 78.76, 78.16, 67.56, 65.22, 65.16, 65.04, 63.74, 62.32, 60.8, 59.82, 59.1, 58.84, 56.5, 55.56].
X1=[31.5, 30.1, 29.9, 29.3, 29.1, 29.1, 28.9, 28.3, 28.8, 29.2, 28.9, 28.3, 26.7, 25.1, 24.9, 25.8, 24.9, 24.9, 24.9, 23.8, 23.4, 24.1, 24.6, 24.4].
X2=[33, 34, 35, 36, 31, 35, 35, 32, 33, 36, 35, 37, 28, 35, 34, 30, 34, 35, 33, 34, 37, 36, 28, 30];
X3=[4, 1, 6, 4, 4, 4, 2, 3; 4, 0; 7, 10, 0, 1, 8, 1, 4, 6, 2, 4, 4, 5, 18, 6].
Model for y=a (1) + a (2) + a (3) * * x1 x2) ^ 2 + a (4) * x2 + a (5) * x3. ^ 2 + a (6) * x3
Deliver a great god