百分率χ～2检验的应用条件

Application conditions ofχ2 test on percentage

百分率的χ2检验在农业科学数据分析中的应用非常普遍,但目前在应用条件上仍存有偏差.本文以一个总体的百分率P是否等于常数P0的χ2检验为例,根据χ2检验模型的来历认为:应用的条件np≥5,nq=n(1-p)≥5,在实际应用时对应的应用条件应该是:m≥5,n-m≥5,而不仅仅是目前教科书的应用条件:np0≥5,nq0=n(1-p0)≥5.本结果将有助于研究人员在应用χ2检验避免偏差,得到更客观的统计结果.

The test on percentage is very common applied in data analysis of agricultural science,but there is still deviation in application conditions.In this paper,we took a example of making a comparison of the overall percentage P and the P〈0 constant,calculated whether two number were equal or not.According to the origin ofχ2 model,the application conditions of np≥5 ,nq=n（1-p）≥5 should be corrected.In the actual application,the application condition should be ：m≥5 ,n-m≥5 ,instead of the relevant content,nP〈0≥5 ,nq0=n（1-P〈0 ）≥5 in the text book.The results will help researchers to avoid deviation in the applica-tion ofχ2 test,and get more obj ective statistical results.