作者stonycindy (Esperanza)
看板Statistics
标题[问题]又是机率...
时间Fri Apr 14 02:53:39 2006
Q1. 若E(X^r)=5^r，r=1,2,3,...，求X的动差母函数M(t)和X之p.m.f.。
Q2. Suppose an airport metal detector catches a person with a metal 99% of the
time. That is, it misses detecting a person with metal 1% of the time.
Assuming independence of people carrying metal, what is the probability
that the first person missed(not detected) is among the first 50 persons?
Answer:0.395
Q3. From 1999-2002 Red Rose Tea randomly placed one of 10 English porcelain
miniature animals in a 100-bag box of Red Rose Tea, selecting from 10
endangered North American animals.
(a) If the customer uses one tea bag per day, how long will it take,
approximately, to obtain a complete collection?
Answer:(a) 8
麻烦写一下算式，
谢谢啦！
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