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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 -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 61.231.246.53
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