作者bbpopo (笨蛋姊姊)
看板Grad-ProbAsk
標題[問題] 關於統計的問題
時間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?
以上這兩題,
第一題的問題在
我的寫法是P(X > 14)=P[Z > (14-0.5-90)/√100*0.9*0.1]
我算出來右邊的數值居然是-25點多
我不知道我那樣的算法對不對
如果是對的話,請問 Z > -25 查表要怎麼查...
而第二題是我完全不知道要怎麼下手...
希望有高手可以指教一下
我一定會大大的感激你/妳的
謝謝
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→ sacrificial:Z值正負3以內就包含了99%以上的機率值 04/03 23:43
→ sacrificial:P(Z > -25) 非常趨近於1了吧 04/03 23:45