作者kevin20250 (喔喔)
看板TransPSY
标题[统计] 简单机率
时间Wed Apr 28 01:00:23 2010
X为中心为150,标准差为42之常态分配
问同时取9个大於1800的机率?
求方法@@
原题目在这
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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※ 编辑: kevin20250 来自: 111.240.58.215 (04/28 01:29)
1F：推 hyt19870301:约0.117，方法是找出Z分数後查表就好了 05/11 02:41
2F：→ kevin20250:取9个的标准差是..? 05/12 12:23
3F：推 hyt19870301:利用加成原理可知X1+X2+....+X9~N(1350,378) 05/19 03:26