C]/=.4 



t 



700- 

 600 

 500- 

 400- 

 300 

 ZOO- 

 ZOO 

 



.02 



CV=.3 



20,000 

 5,000 



1,000 



500 



AccuracL/ 





CV=.5 



-y ^20,000 



\\ ^ 5, 000 





2,000 





1,000 

 ^500 



















.03 .04 



Accurocy 



.05 



20, 000 

 5,000 



2,000 

 /,000 

 500 



.05 



Accuraccy 



■20,000 

 5000 



C V=.6 



.02 



.03 .04 .05 



Accurc^cL/ 



20, 000 

 5.000 



CV=.8 



.03 -04 



AcciyracL/ 



.05 



Figure 1. — G-raplis stiowing the number of trees in the sample needed 

 for accuracies of two percent to five percent, for sale 

 sizes of 500 to 20,000 trees, and coefficients of varia- 

 tion of oS to o8. 



-7- 



