作者oceanboy0605 ()
看板Statistics
标题[问题]统计三个问题
时间Fri Jan 4 22:01:15 2008
以下我有统计三题我各位帮忙，除了有过程之外，
最好需要有详细解说我会比较容易了解～谢谢
1.求算二项分配的众数
2.If 5% of the tires purchased by a cab company last less than 6 months
and if 20 tires are purchased, calculate the probability that at most
2 of the tires will expire in six months using.
If the mean length of life a tire 2 years. Use the exponential distribution
to calculate the probability that the life of a tire will be less than
6 months?
3.Suppose the lifelime of an electronic tube has an exponential distribution
with a mean time of 1/λ hours. Find the expected lifelime of a tube,given
that the tube has lasted at least T hours.
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※ 发信站: 批踢踢实业坊(ptt.cc)
◆ From: 218.167.62.1
1F：推 ashugh:第2题第一部分就是binomial,第二部分跟第三题用exponential 01/04 22:05
2F：→ ashugh:distribution去算就ok了啊! 01/04 22:06
3F：→ ashugh:至於第一题直觉是F(x)=0.5 01/04 22:08
4F：推 ashugh:感觉有说跟没说一样XD! 2.1 P(X<=2) X~bi(n=20,p=0.95) 01/04 22:11
5F：→ ashugh:2.2 P(Y<0.5) Y~exp(2) Q3 E(Y given Y>T) Y~exp(1/λ) 01/04 22:14
6F：推 lbbear:f(a)>f(a+1) & f(a)>f(a-1) 满足的都是众数 01/05 20:32