推 hyt19870301:約0.117，方法是找出Z分數後查表就好了 05/11 02:41
→ kevin20250:取9個的標準差是..? 05/12 12:23
推 hyt19870301:利用加成原理可知X1+X2+....+X9~N(1350,378) 05/19 03:26
X為中心為150,標準差為42之常態分配
問同時取9個大於1800的機率?
求方法@@
原題目在這
an elevator carries nine people in a load ,the weights of people vary accordind
to many factors buy may be decribed by a distribuion with mean 150 pounds and
standard deviation 42 pounds. over many loads,each of nine people,about what
percentage of loads will exceed the safe load limit of 1800 pounds?
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※ 編輯: kevin20250 來自: 111.240.58.215 (04/28 01:29)