H. E. Soper 
113 
Fig. 2. 
•0 - 9 
Values of r. 
Figs. 4 and 5. 
of cot- tm:/^ ^ 
75 O <sdm/i^M 
C© ^-y-c^tc^v.-o ? j. coe^ytowv^rf < -»i o m.fi./*. s -of 
•0 -9 -8 -.7 -6 
Biometrika ix 
■l 
•9 1- 
15 
