Table B-3. Calculated number of quantitative samples required to estimate unionid species density at 

 Case-IH (RM 488.5) in (a) 1994 (72 samples collected) and (b) 1985 (6 samples collected) 

 within x% of the actual density with a 0.05% probability of being incorrect. Based on the 

 formula ; n = [(2 SD) ^ (xM)]-, where : n = number of samples required, SD = standard 

 deviation, x = desired level of accuracy (i.e., 10% = 0.1), and M = mean unionid density based 

 on samples collected Numbers within rectangles indicate the number of samples collected 

 met or exceeded the number of samples required for each level of accuracy (%). 



Page B-4 



Whitney et al., Unionid Sun'ey - Reach 1 5 UMR 



