# 求統計學高手解答 (三)

麻煩請附上解題過程 謝謝

四、The weekly earnings of students in one age group are normally distributed with a

standard deviation of 36 dollars. A researcher wishes to estimate the mean

weekly earnings of students in the age group. Find the sample size needed to

assure with 98% confidence that the sample mean will not differ from the

population mean by more than 3 dollars. (94 年雲科大資管所)

### 1 Answer

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- 1 decade agoFavorite Answer
n=Z平方乘母體變異數/標準誤平方

98%查表得2.33 母體變異數=36 e=表準誤=3

n=2.33*2.33*36*36/3*3=781.7616

無條件進位n=782

2008-06-29 00:52:03 補充：

母體標準差=36

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