182 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



Length-Frequencies, Group II, Females ; Nelson Buoy, 

 June 1909. Comparison with Normal Curve of Error. 



Mean length 

 in cents. 



Frequency. 



Smoothed 

 frequency. 



Deviation 

 from mode. 



Theoretical 

 frequency. 



15-5 



2 



2 



2-4 



1-08 



16-5 



6 



6. 



1-9 



317 



17-5 



10 



9 



1-4 



7-26 



18-5 



11 



14-7 



0-99 



11-85 



19-5 



23 



16-3 



0-5 



17-08 



20-5 



15 



20 



— 



19-37 



21-5 



22 



14 



0-5 



17-08 



22-5 



5 



10-3 



0-99 



11-85 



23-5 



4 



3 



1-4 



7-26 



24-5 



— 



1-7 



1-9 



3-17 



25-5 



1 



1 



2-4 



1-08 



n = no. of observations = 98. 

 Arithmetic average = 20*03. 

 Empirical mode = 205. 

 2 £ 2 = Sum of errors squared == 409 '88. 



Standard deviation, a, 

 Maximum frequency = 



a V 2 



2-019. 



19-37. 



