N˚	Factors			$x_{1} x_{2}$	$x_{1} x_{3}$	$x_{2} x_{3}$	$x_{1}^{2}$	$x_{2}^{2}$	$x_{3}^{2}$	$Y_{1}$	$S_{u}^{2} (Y_{1})$
N˚	$x_{1}$	$x_{2}$	$x_{3}$	$x_{1} x_{2}$	$x_{1} x_{3}$	$x_{2} x_{3}$	$x_{1}^{2}$	$x_{2}^{2}$	$x_{3}^{2}$	$Y_{1}$	$S_{u}^{2} (Y_{1})$
1	+	+	0	+	0	0	+	+	0	202	11.0
2	+	-	0	-	0	0	+	+	0	180	9.0
3	-	+	0	-	0	0	+	+	0	175	9.0
4	-	-	0	+	0	0	+	+	0	160	12.0
5	+	0	+	0	+	0	+	0	+	245	8.0
6	+	0	-	0	-	0	+	0	+	211	12.0
7	-	0	+	0	-	0	+	0	+	189	11.0
8	-	0	-	0	+	0	+	0	+	176	8.0
9	0	+	+	0	0	+	0	+	+	209	9.0
10	0	+	-	0	0	-	0	+	+	211	11.0
11	0	-	+	0	0	-	0	+	+	196	8.0
12	0	-	-	0	0	+	0	+	+	169	9.0
13	0	0	0	0	0	0	0	0	0	206	7.0
14	0	0	0	0	0	0	0	0	0	214	5.0
15	0	0	0	0	0	0	0	0	0	211	15.0
The values (+), (-) and 0 should be used in the matrix