POrSSON'S PROn ABILITY SUMMATION 



621 



TABLE II 

 c=number of occurrences of the event per sani[)Ie. 

 nt = number of samples with exactly c occurrences. 

 / = number of samples with at least c occurrences. 

 /^ = relative frequency of at least c occurrences per sample. 



al Alpha particles 

 total = 10097 

 average =3. 87 



a2 Alpha particles 

 total = 10094 

 average = 7 . 74 



a3 Deaths of aged 



total = 903 

 average =0.82 



a4 Deaths of aged 



total = 2364 



average =2. 16 



a5 Telephone lines 



in use* 



total = ? 



average =4. 32 



a6 Bacilli 

 total = 1927 

 average =1.93 



bl Yeast cells 

 total =720 

 average = 1.80 



b2 Yeast cells 

 total = 1872 

 average =4. 68 



