74 MAINE AGRICULTURAL EXPERIMENT STATION. I914. 



filling by pouring tlie grain into tbe 'bucket. The probable error 

 of this difference is ±.0529, which clearly signifies that the 

 increase is due to the method of filling and not to chance. The 

 standard deviation of Method II is higher than of Method I. 

 The difference .0503 is slightly less than twice the probable 

 error ±.0264 showing that the two methods are about equal in 

 variabihty. Further evidence of this is shown in the coefficients 

 of variability which differ by .0369+. 1044 the difference being 

 less than its probable error. 



Table 2. 

 Variation Constants in Weight per Bushel of Lincoln Oats. 





Mean. 



Standard 



deviation 



—lbs. 





Method. 



Per cent. 



Weight per bushel 

 —lbs. 



Coefficient 

 of variation. 



I 



54 . 090 



34.6176±.0357 



.5291 ±.0178 



1.5284 ±.0729 



II 



57.835 



37. 0144 ±.0391 



.5794±.0195 



1.5653 ±.0747 



Ill 



58.585 



37. 4944 ±.0320 



.4744±.0160 



1.2653 ±.0604 



IV 



60.385 



38.6464±.0219 



.32-54±.0110 



0.8420 ±.0402 



When the grain is settled by shaking, 'the mean weight per 

 bushel is greatly increased. This is seen by comparing Method 

 IV with Method I. The mean weight per bushel according to 

 Method IV is 4.0288rh.04i9 lbs. higher than that of Method I. 

 Such a difference, 100 times its proibable error, clearly signifies 

 that the higher mean is due to the method of handling the grain. 

 In addition to raising the mean, Method IV also lowers the 

 standard deviation by the amount of .2037=^.0209 lbs. This 

 difference is significant in that it is about 10 times its probable 

 error. Hence it is clear that settling the grain lessens the vari- 

 ability of the determinations. This is further substantiated in 

 the coefficients of variation. Here the difference is 0.6864, 

 which is about 8 times its probable error ±.0833. Similarly 

 the effect of shaking is shown in Method III as compared with 

 Metihbd 11. One shaking raises the mean 0.48001^.0505 lbs. 

 and lowers the standard deviation .I050±:.0'232 lbs. The rela- 

 tive variability also decreases, as is seen in the coefficients of 

 variation, giving a difference of 0.3000=^.0961. In each of 

 these the magnitude of the difference in relation to its probable 



