问题如下图:
选项:
A.
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解释:
老师您好,想问一下,Z<-0.11是等于Z>0.11的概率吧,为何等于1-P(Z>0.11)?
星星_品职助教 · 2019年09月18日
同学你好,
P(Z<-0.11)确实等于P(Z>0.11),但本题最终计算是不需要用到P(Z>0.11)的。我把解题过程详细写一遍你看下。
本题本质是要查表得到P(Z<-0.11)的概率,但因为很多的标准整体分布表里只可以查到正数,所以必须将P(Z<-0.11)做转化,P(Z<-0.11)通过对称等于P(Z>0.11),所以问题转化为了查P(Z>0.11)的概率。
但标准正态分布表是一个累积概率的表格,所以只能查Z小于多少,如果题目一旦要查Z大于多少,还是要通过对称的方式再做转化。所以将P(Z>0.11)通过对称进一步转化为了1-P(Z<0.11),即1-N(0.11)。进而查表计算得出答案。
加油
NO.PZ2018062016000088问题如下 A stoobeying normstribution ha mereturn of 6% ana stanrviation of 18%. The probability for the stock's return to fall less th4% is:N(0.11) = 0.5438 A.37.91%B.45.62%C.57.68% B is correct. Firstly, stanrze the originnormstributionZ= (x-6%)/18%, so P(x 4%) = P( Z -0.11).NotithN(-0.11) = 1- N(0.11). Baseon the given contion, N(0.11) = 0.5438, so N(-0.11) = 1-0.5438 = 0.4562 = 45.62% 另外题目给的是N也是累积概率的意思吗?为什么给的不是F
NO.PZ2018062016000088问题如下 A stoobeying normstribution ha mereturn of 6% ana stanrviation of 18%. The probability for the stock's return to fall less th4% is:N(0.11) = 0.5438 A.37.91%B.45.62%C.57.68% B is correct. Firstly, stanrze the originnormstributionZ= (x-6%)/18%, so P(x 4%) = P( Z -0.11).NotithN(-0.11) = 1- N(0.11). Baseon the given contion, N(0.11) = 0.5438, so N(-0.11) = 1-0.5438 = 0.4562 = 45.62% 为什么能看出来是FX、有没有可能是T分布、0.11指的就是criticpoint右边区域的面积呢?
NO.PZ2018062016000088 45.62% 57.68% B is correct. Firstly, stanrze the originnormstributionZ= (x-6%)/18%, so P(x <4%) = P( Z<-0.11). NotithN(-0.11) = 1- N(0.11). Baseon the given contion, N(0.11) = 0.5438, so N(-0.11) = 1-0.5438 = 0.4562 = 45.62% 这道题哪句话说的是Z分布,另外x为什么是4呢?不太明白这道题目的意思
45.62% 57.68% B is correct. Firstly, stanrze the originnormstributionZ= (x-6%)/18%, so P(x <4%) = P( Z<-0.11). NotithN(-0.11) = 1- N(0.11). Baseon the given table, N(0.11) = 0.5438, so N(-0.11) = 1-0.5438 = 0.4562 = 45.62%请问考试时如何查表呢?
老师那个0.11是用 (4-6)/18得到的吗?