Student 267 
This is equal to 
^-^ ^tf- + 2g |i + 2 + ... + - 1)1 + {r^ + 2-^ + ... + (i - iy\ 
~ n \ 6 ^ 
12)1 ' 
'^^'"H^ 12 /r ■ 
This is clearly additive for any number of ties so that if 2',. = S ^'^ ^ - 
summing for all the ties on the w side and similarly T,, for the y side 
and substituting in (vii) 
6 n ^ 
6 1) /V 6 n 
(x), 
6 \J i)_^^,^W- 
So that if and 2',^ do not differ appreciably 
In estimating 7'^: or Ty each pair contributes i, 
triplet „ 2, 
quartet „ 5, 
quintet „ 10, 
and so on. For example, if the x ranks for a sample of 10 were 
1, 2i, 2|, 5, 5, 5, 8^, Sh, 81, S^, 
