OF ATTRIBUTES IN STATISTICS. 



275 



If a, = 2 = 0, i.e., if equality of contraries subsist amongst the first and second 

 order groups, we have 



(U) , 



(9). 



The following short table gives the values of K and \/ K for different values of Q. 

 The values of K and \/K corresponding to negative Q's are the reciprocals of those 

 corresponding to the positive values : 



Association and Correlation. 



26. The theorem already referred to, due to Mr. W. F. SHEPPARD,* forms a 

 connecting link between BRAVAIS' coefficient of correlation and the association 

 coefficient in the case of normal correlation. If the divisions between A and a, 

 B and /8. &c., are the means of the corresponding variables 



' Phil. Trans.,' A, 1898, vol. 162, p. 101. 

 2 N 2 



