æ±æ»ä½æ¹å·®çåºé´ä¼°è®¡ç»è®¡é(n-1)S^2/Ï^2~Ï^2(n-1) α=1-0.95=0.05,α/2=0.025,1-α/2=0.975 æ»ä½æ¹å·®ç95%置信åºé´ [(n-1)S^2/Ï^2α/2(n-1) (n-1)S^2/Ï^2(1-α/2)/(n-1)] =[30*0.5477^2/46.98 30*0.5477^2/16.79] =[ 0.1912 0.536] æ åå·®ç95%置信åºé´ [0.4373 0.732]
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