CORRELATION 47 1 



read across the table, we see that the percentage of females falls 

 slightly as we get into high speeds, but the fall is very slight. 

 The percentages as to color vary but slightly, except in black, 

 which decidedly increases with high speed, and in gray, which as 

 decidedly falls off. 



Applying Yule's formula to the study of these figures, let us, 

 for example, take the bay color and inquire as to the measure 

 of correlation between this color and high speed : 



Total number of bays 7>376 



Number of bays at or below 2 : 15-2 : 16 502 



Total number of performers 13,879 



Total number of performers at or below 2 : 15-2 : 16 , 915 

 Number not bays at or below 2 : 15-2 : 16 is 915 502 = 413 

 Number of bays above 2 : 15-2 : 16 is 7376 502 = 6874 

 Number not bays above 2:15-2 : 16 is 13,879 -(7376 + 413) = 6090 



Arranging these values according to Yule's formula, we have 



This gives as a measure of the association of the bay color 

 and speed, 



6090 x 502 - 6874 x 413 = , Q g 

 6090 x 502 + 6874 x 413 



While this result, 0.038, shows that the bays have furnished 

 slightly more than their share of the high-speed trotters, it is 

 doubtful whether this coefficient is large enough to enable us to 

 assert any decided correlation. 



In much the same way exhaustive studies should be made in all 

 lines of breeding, and at any expense of time and labor, in order 

 that we may possess ourselves of reliable information in regard 

 to as many details as possible concerning the relations of notable 

 characters in our most valuable races. 



