作者bbpopo (笨蛋姊姊)
看板Grad-ProbAsk
标题[问题] 关於统计的问题
时间Fri Apr 3 21:14:29 2009
1.
an urn contain white and 9 red marbles.
a marble is drawn from the urn
100 times in succession with replacement.
find the probability of drawing
more than 14 red marbles.
approximately,use the central limit thm.
2.
let X be the number of successes in n
independent trials with the probability
of success on each trial equal to p
the null hypothesis
Ho: p <=0.5 is to be tested against the
alternative hypothesis
H1:p > 0.5
the null hypothesis is rejected if X = n
for what value of p is the power
function of this test equal to 0.9?
以上这两题，
第一题的问题在
我的写法是P(X > 14)=P[Z > (14-0.5-90)/√100*0.9*0.1]
我算出来右边的数值居然是-25点多
我不知道我那样的算法对不对
如果是对的话，请问 Z > -25 查表要怎麽查...
而第二题是我完全不知道要怎麽下手...
希望有高手可以指教一下
我一定会大大的感激你/你的
谢谢
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1F：→ sacrificial:Z值正负3以内就包含了99%以上的机率值 04/03 23:43
2F：→ sacrificial:P(Z > -25) 非常趋近於1了吧 04/03 23:45