Media 	       Desvio
 X1  	        28.1		5.76
 X2 		26.6		5.85
 X3  	 	35.4		3.82
 X4  	 	34.2		5.12
 X5   		23.6		3.76
 X6  		22.0		3.93
 X7  		22.7 		4.03