作者eewwdog (黯淡)
看板Math
标题[机统] 指数型计算题
时间Wed Apr 6 04:13:10 2011
A system to function as long as at least 3 of its 5 processors continue
to operate. Suppose processors lifetime are exponentially distributed
with mean L. Find the expected system lifetime.
这题我有几个地方不确定他真正的意思
as long as at least 3 of its 5 processors 是指五个里面至少要取三个的意思吗?
如果是的话 那是不是有三种情况 : 取三种 ,取四种,和取五种?
第二
题目最後说 Find the expected system lifetime 是要求什麽? 是P[3<=X<=5]?
如果题目改成A system to function as long as 3 of its 5 processors
那是不是表示从五个当中只要取三个就可以了??
如果题目又问算此系统的PDF? 那又是要算甚麽?
不好意思
问题多了点
请大家帮忙
谢谢大家
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1F：→ tibicos :expected lifetime 是指lifetime的期望值（平均值） 04/06 07:52