THE CLASSES OF FREQUENCY POLY<i()\S. 35 



Example of calculating tlie theoretical curve corre- 

 sponding vvitli observed data. (Fig. 6.) 



Distribution of frequency of glands in the right fore leg of ~COO female 

 swine (integral variates): 



Number of glands 0123456789 10 

 Frequency 15 209 365 482 414 277 134 72 22 8 2 



Assume the axis yy' ( Vni) to pass through ordinate 4, then: 

 V V-Vm f /(F-Fm) f(V F>) 2 /(F- F*)3 /(F Fm) 



2 2000 998 6148 3872 48568 



Vl = 998 -*- 2000 = .499. 



r a = 6148 -*- 2000 = 3.074. 



v, = 3872 -* 2000 = 1.936. 



v 4 = 48568 -*- 2000 = 24.284. 



/n=0; A = 4-. 499 =3.501. 



Ma = 3.074 ( .499) 2 = 2.824999. 



M 3 = - 1.936 - 3(- .499 X 3.074) + 2(- .499)' = 2.417278. 



M 4 = 24.284 -4(-. 499 X- 1.936) -f 6(.249001 X 3.074) - 3(- 499)* = 24.826297, 



(2.417278)* _ 5.843232929 _ 

 Pl (2.824999)3 " 22.545241683 ~ 

 _ 24.826297 _ 24.826297 _ 



^^ 



_ 

 (2.824999^ - 7.98061935 



.259 X (6.111)2 



4(12.443 - .778)(6.222 - 6.778) 

 6(3.11082- 0^25918 - 

 .555o9 



,21.9857 



a- K V.259178 ~^- = .31115. 



D- 1.680774 X .3111 = .5230. 

 Z).a- .5230 X 19.9857 = 10.4519. 



Z= .840387 4/16 X 20.9857 -f 0.25918 X (21.9857) 2 = 18.0448. 

 18.0448- 10.4519 = ^^ 



