higher. There is no significant difference in average numbers of individuals 

 of given age or sex between the two samples. Since the total populations of 

 the samples are equivalent, there is likewise no difference in proportions 

 in each age group. 



Table 2. 



115th, 16th United States Census, Vol. 2, Characteristics of Population. 



Farm and Non-Farm 



The samples were then divided into farm and non-farm residences retain- 

 ing the same age and sex categories. The "t" tests were used again for 

 each age and sex category. The highest value for "t" obtained was 1.21 

 (p = 0.35). In the sub-samples taken as a whole the numbers of non-farm 

 and farm population show no differences. It was felt that in spite of the 

 similarity in numbers, there might be the possibility that the proportion 

 of non-farm males to total males might vary. Accordingly these were tested 

 in similar fashion. The maximum "t" obtained was 1.81 (p =: 0.12). The 

 proportion of non-farm males to total males for all age categories then 

 showed no significant difference. That category which did show a high 

 value (1.81) was males 0-5 years old, reflecting probably the recent in- 

 crease in fertility. 



Change in Age Distribution, 1930-1950 



The preceding tests demonstrate that there are no major differences be- 

 tween the two population distributions either grossly or by relatively small 

 age and sex categories. The next question was whether this similarity in 



