data quad1;
input  Cow  fi ed  Yield;
cards;
 1  50  0.8  5731.05
 2  50  1.0  4607.40
 3  50  1.2  5169.25
 4  50  1.4  6345.16
 5  50  1.6  6477.83
 6  60  0.8  4970.22
 7  60  1.0  5263.30
 8  60  1.2  5414.44
 9  60  1.4  7102.82
10  60  1.6  6670.46
11  70  0.8  6371.27
12  70  1.0  5594.80
13  70  1.2  6033.55
14  70  1.4  7248.72
15  70  1.6  7288.52
16  80  0.8  5499.63
17  80  1.0  6644.66
18  80  1.2  6880.00
19  80  1.4  7542.48
20  80  1.6  7916.68
21  90  0.8  6758.12
22  90  1.0  7547.07
23  90  1.2  7855.26
24  90  1.4  7879.89
25  90  1.6  7938.86
26 100  0.8  6371.87
27 100  1.0  6996.44
28 100  1.2  7095.97
29 100  1.4  8360.18
30 100  1.6  8206.27
31 110  0.8  6750.66
32 110  1.0  7567.50
33 110  1.2  8222.51
34 110  1.4  8336.00
35 110  1.6  8967.15
36 120  0.8  6575.70
37 120  1.0  8261.29
38 120  1.2  7488.05
39 120  1.4  9299.34
40 120  1.6  8629.58
41 130  0.8  7165.49
42 130  1.0  7047.87
43 130  1.2  7764.65
44 130  1.4  8740.82
45 130  1.6  9101.40
46 140  0.8  7608.81
47 140  1.0  7843.19
48 140  1.2  8400.67
49 140  1.4  9421.99
50 140  1.6  9010.69
;

proc glm data=quad1;
model yield = ed fi fi*fi;
run;