※ 引述《[email protected]》之铭言： > The American Council of Life Insurance reports the mean life insurance > in force per covered family in the Life Insurance Fact Book. Assume that > the standard deviation of life insurance in force is $50900. > Determine the probability that the sampling error made in estimating > the population meanlife insurance in force by that of a sample of 500 > coverd families will be $2000 or less. > 知道答案但是不知道怎麽算~谢谢 n=500, 大概可用常态近似. _ X approximated ～ N(μ, 50900/√(500)) _ 问: P[|X-μ|≦2000] = ? -- 来自统计专业的召唤... 无名小站 telnet://wretch.twbbs.org Statistics (统计方法讨论区) 成大计中站 telnet://bbs.ncku.edu.tw Statistics (统计方法及学理讨论区) 盈月与繁星 telnet://ms.twbbs.org Statistics (统计：让数字说话) 交大资讯次世代 telnet://bs2.twbbs.org Statistics (统计与机率) ★本文未经本人同意请勿转载; 回覆请勿全文引用, 请仅留下直接涉及部分。 -- 夫兵者不祥之器物或恶之故有道者不处君子居则贵左用兵则贵右兵者不祥之器非君子 之器不得已而用之恬淡为上胜而不美而美之者是乐杀人夫乐杀人者则不可得志於天下 矣吉事尚左凶事尚右偏将军居左上将军居右言以丧礼处之杀人之众以哀悲泣之战胜以 丧礼处之道常无名朴虽小天下莫能臣侯王若能守之万物将自宾天地相合以降甘露民莫 之令而自均始制有名名亦既有夫亦将知止知止可以不殆譬道之在天 163.15.188.87海