xc 



Tables for Statisticians and Biometricians 



[XII 



Parsons proceed to distribute the femora of 45, 46 and 47 mm. by other charac- 

 teristics between the sexes. There are serious objections to this method of sexing, 

 and Parsons obtains distributions which in the female case tail off far too rapidly 

 on the side of the larger bones, and in the male case far too rapidly on the side of 

 the smaller bones. 



While Dwight's limits are arbitrary and only roughly approximate, we may 

 still use them in illustration of the present method. 



We have for the truncated female distribution : 



and for the truncated male distribution : 



44-5 and 47'5 will be our dichotomic values, and remembering this we find 



For females : 



d = 2-62644, 2 2 = 2-639,192, 



whence ^i='3826, 



and Table XII gives us h' = '9863, 



^ 2 = -7823, ^3=1-1941. 

 Thus by the relations on the previous page 



a =2-0547 mm., AT =103-9, 

 OB = 2-0266 mm., Mean = 44'5 - OB = 42'47 mm. 



For males : 



d = 2-76829, 2 2 = 3-448,345, 



whence fa = -4500, 



and Table XII gives us li = '6400, 



Thus we obtain 



a = 2-5634 mm., N= 166*6, 



OB = 1-6406 mm., Mean = 47 "5 + OB = 49'14 mm. 

 Parsons sexes 105 bones as female, and from his measurements I find 



Mean = 42-47 mm., Standard Deviation = 1'996 mm. 

 He has 174 bones which he sexes as male, and for these I find 



Mean = 49'22 mm., Standard Deviation = 2'530 mm. 



