n 



N 



where S— is estimated from S= {^) 

 - E (f) 



y 



E = accuracy standard 



and n = n — n^, 



ir. - * 



YIII. SAlvIPLE SIZE NEEDED FOR ESTB'IATING SCALED VOLULE 



(BASIS FOR FIGURE 2) 



n 



^ 2 - 2 r 



+ 2 r 



1 



JO. 



C-l + 2r) 



N 



v/here n = sample size 



r =r correlation coefficient of tree measured 

 volumes and check scaled voluiaes 



Cm = cost of check scaling a sample tree 



Cn = cost of tree measuring a sample tree 



E = accuracy 



CV= coefficient of variation 

 N = number of trees in sale 



-46- 



