【摘要】 <正> 确定样本含量,是统计学调查实验设计的主要内容之一。样本含量不足,达不到应有的精度;样本含量过多,又会造成人力物力和时间的浪费。样本含量可凭估计,计算或查表确定,但这些方法或失之过粗,或应用不便。图更多还原

【Abstract】 A sample size nomogram,which is based on theformulars（1）to（5）described in this paper,hasbeen designed.This nomogram can be used to esti-mate the sample size for t-tests of three types（co-mparison of sample mean with a population mean,comparison of two sample means and comparison ofthe paired data）,and that of two kinds of powerof test （0.5,0.05）.This nomogram is composed ofnomogram I to 5.In application,a straight line isdrawn to intersect three scaled axes,two intersect-ing points being the known values,the third givingthe value of the unknown.To use the nomogram 1to 4,the value for n can be obtained from D（s/d）and n′（standing for t_α/2,n′or t_α/2,n′+t_β,n′）;to use nomogram 5,the value for n₂（when n₁≠n₂）is obtained from n（when n₁=n₂=n）and n₁（when n₁≠n₂）.更多还原