作者tokyo291 (工口工口)
看板Math
標題[機統] 應該是屬於CLT
時間Fri Jan 25 00:06:26 2013
The waiting period from the time a book is ordered until it is
receieved is a random variable with mean seven days and standard
deviation two days. If you want to be 95% sure that you received a
book by a certain date, how early should you order the book?
請問這一題該用中央極限定理去解嗎?
不知道是不是我想得太複雜了...
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推 jklkj :謝比雪夫 01/25 00:41
→ tokyo291 :可是Chebyshev's是機率>=或<=某個值.這樣有合題意嗎? 01/25 00:44
推 jklkj :題目是問什麼 01/25 00:46
→ tokyo291 :to be 95% sure that you received a book 01/25 00:47
推 jklkj :你一定要收到那不就小於等於嗎 01/25 00:51
→ tokyo291 :對耶XD是我想太多= = 01/25 00:52