\\ii Tables for Slut !*t i<-;<i a* and Binimtrii-litii* (T VI 



Hence using formula (ii) p. xiii : 

 (- log F)= 252 95315 + -31 [14-9957:}] 



31 x -9039 -69 x -5239 



- - x -43393 - x -43394 



o o 



= 252-953151 



+ 4-648G8 



> = 257-55542. 



- -04G41 

 Hence log F = - 257'55542 = 258-44458, 



.F=2-7834/10", 

 which measures the improbability required. 



TABLE V (pp. 1218) AND TABLE VI (p. 18) 



Probable Errors of Means, Standard Deviations and Coefficients of Variation. 

 (Table V calculated by Winifred Gibson, B.Sc.; Table VI by Dr Raymond Pearl 

 and T. Blakeman, M.A. Biometrika, Vol. iv. pp. 385393.) 



If m be a mean, a a standard deviation and F=100<r/w a coefficient of 

 variation, for a population of n, we have 



Probable Error of Mean 



-6744898o/Vn-K<r ...................... (xi), 



Probable Error of Standard Deviation 



= -G744898o-/V2n = ^a ........................... (xii), 



Probable Error of the Coefficient of Variation 



= -6744898 Fxl + 2 j ^ .................. ("), 



= -6744898/^271 x ^ 



= X X ^ ................................................... ( xiv >- 



Table V gives ^ and , for each value of n up to 1000, Table VI gives -ty for 

 each value of V proceeding by units from to 50. 



When the frequency n is greater than 1000, the tables may still be used by 

 taking out a square factor, which can be divided out at sight. 



Illustration (i). n = 2834 = 4 x 70S-5. 



n = 708, x , = -02.530 ; H = 709, x. = '02533. 

 .-. w = 708-5, X , = -02534, and .-. for n = 2834, 

 we have x , = '01267. 



Illustration (ii). In the case of the 900 Bavarian crania of the Illustration (iii) 

 to Table II the values 



m = 83-069, a = 3-482, 



