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f(k,&nbsp;n,&nbsp;p) is monotone increasing for k&nbsp;<&nbsp;M and monotone decreasing for k&nbsp;>&nbsp;M, with the exception of the case where (n&nbsp;+&nbsp;1)p is an integer. In this case, there are two values for which f is maximal: (n&nbsp;+&nbsp;1)p and (n&nbsp;+&nbsp;1)p&nbsp;−&nbsp;1. M is the most probable outcome (that is, the most likely, although this can still be unlikely overall) of the Bernoulli trials and is called the mode.
 
f(k,&nbsp;n,&nbsp;p) is monotone increasing for k&nbsp;<&nbsp;M and monotone decreasing for k&nbsp;>&nbsp;M, with the exception of the case where (n&nbsp;+&nbsp;1)p is an integer. In this case, there are two values for which f is maximal: (n&nbsp;+&nbsp;1)p and (n&nbsp;+&nbsp;1)p&nbsp;−&nbsp;1. M is the most probable outcome (that is, the most likely, although this can still be unlikely overall) of the Bernoulli trials and is called the mode.
   −
''f''(''k'',&nbsp;''n'',&nbsp;''p'')对''k''&nbsp;< ''M''&nbsp是单调递增的,对''k''&nbsp;> ''M''&nbsp是单调递减的,但(''n''&nbsp;+&nbsp;1)''p''是整数的情况除外。在这种情况下,有(''n''&nbsp;+&nbsp;1)''p'' 和 (''n''&nbsp;+&nbsp;1)''p''&nbsp;−1&nbsp两个值使''f''达到最大。''M'' 是伯努利试验最有可能的结果(也就是说,发生的可能性最大,尽管仍然存在不发生的情况) ,被称为模。
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''f''(''k'',&nbsp;''n'',&nbsp;''p'')对''k''&nbsp;< ''M''&nbsp;是单调递增的,对''k''&nbsp;> ''M''&nbsp;是单调递减的,但(''n''&nbsp;+&nbsp;1)''p''是整数的情况除外。在这种情况下,有(''n''&nbsp;+&nbsp;1)''p'' 和 (''n''&nbsp;+&nbsp;1)''p''&nbsp;−1&nbsp;两个值使''f''达到最大。''M'' 是伯努利试验最有可能的结果(也就是说,发生的可能性最大,尽管仍然存在不发生的情况) ,被称为模。
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It can also be represented in terms of the regularized incomplete beta function, as follows:
 
It can also be represented in terms of the regularized incomplete beta function, as follows:
   −
在<font color="#ff8000">正则化不完全的\beta函数 regularized incomplete beta function </font>下,它也可以表示如下: <ref>{{cite book |last=Wadsworth |first=G. P. |title=Introduction to Probability and Random Variables |year=1960 |publisher=McGraw-Hill |location=New York  |page=[https://archive.org/details/introductiontopr0000wads/page/52 52] |url=https://archive.org/details/introductiontopr0000wads |url-access=registration }}</ref>
+
在<font color="#ff8000">正则化不完全的beta函数 regularized incomplete beta function </font>下,它也可以表示如下: <ref>{{cite book |last=Wadsworth |first=G. P. |title=Introduction to Probability and Random Variables |year=1960 |publisher=McGraw-Hill |location=New York  |page=[https://archive.org/details/introductiontopr0000wads/page/52 52] |url=https://archive.org/details/introductiontopr0000wads |url-access=registration }}</ref>
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* The median is unique and equal to ''m''&nbsp;=&nbsp;[[Rounding|round]](''np'') when |''m''&nbsp;−&nbsp;''np''|&nbsp;≤&nbsp;min{''p'',&nbsp;1&nbsp;−&nbsp;''p''} (except for the case when ''p''&nbsp;=&nbsp;{{sfrac|1|2}} and ''n'' is odd).<ref name="KaasBuhrman"/>
 
* The median is unique and equal to ''m''&nbsp;=&nbsp;[[Rounding|round]](''np'') when |''m''&nbsp;−&nbsp;''np''|&nbsp;≤&nbsp;min{''p'',&nbsp;1&nbsp;−&nbsp;''p''} (except for the case when ''p''&nbsp;=&nbsp;{{sfrac|1|2}} and ''n'' is odd).<ref name="KaasBuhrman"/>
   −
*中位数是唯一的并且等于''m''&nbsp;=&nbsp;[[Rounding|round]](''np''),此时|''m''&nbsp;−&nbsp;''np''|&nbsp;≤&nbsp;min{''p'',&nbsp;1&nbsp;−&nbsp;''p''}(''p''&nbsp;= \\sfrac{1}{2}&nbsp; 和 ''n'' 是奇数的情况除外)
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*中位数是唯一的并且等于''m''&nbsp;=&nbsp;[[Rounding|round]](''np''),此时|''m''&nbsp;−&nbsp;''np''|&nbsp;≤&nbsp;min{''p'',&nbsp;1&nbsp;−&nbsp;''p''}(<math>''p''&nbsp;=&nbsp;{{sfrac|1|2}}</math>和 ''n'' 是奇数的情况除外)
    
which implies the simpler but looser bound
 
which implies the simpler but looser bound
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For p = 1/2 and k ≥ 3n/8 for even n, it is possible to make the denominator constant:
 
For p = 1/2 and k ≥ 3n/8 for even n, it is possible to make the denominator constant:
   −
对于''p''&nbsp;=&nbsp;1/2且''n''是奇数,任意''m''满足\\sfrac{1}{2}(''n''&nbsp;−&nbsp;1)&nbsp;≤&nbsp;''m''&nbsp;≤&nbsp; \\sfrac{1}{2} (''n''&nbsp;+&nbsp;1)是一个二项分布的中位数。如果''p''&nbsp;=&nbsp;1/2且''n'' 是偶数,那么''m''&nbsp;=&nbsp;''n''/2是唯一的中位数:
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对于''p''&nbsp;=&nbsp;1/2且''n''是奇数,任意''m''满足{{sfrac|1|2}} (''n''&nbsp;−&nbsp;1)&nbsp;≤&nbsp;''m''&nbsp;≤&nbsp; {{sfrac|1|2}} (''n''&nbsp;+&nbsp;1)是一个二项分布的中位数。如果''p''&nbsp;=&nbsp;1/2且''n'' 是偶数,那么''m''&nbsp;=&nbsp;''n''/2是唯一的中位数:
    
<math>F(k;n,p) \geq \frac1{\sqrt{2n}} \exp\left(-nD\left(\frac{k}{n}\parallel p\right)\right);</math>
 
<math>F(k;n,p) \geq \frac1{\sqrt{2n}} \exp\left(-nD\left(\frac{k}{n}\parallel p\right)\right);</math>
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For ''k'' ≤ ''np'', upper bounds can be derived for the lower tail of the cumulative distribution function <math>F(k;n,p) = \Pr(X \le k)</math>, the probability that there are at most ''k'' successes. Since <math>\Pr(X \ge k) = F(n-k;n,1-p) </math>, these bounds can also be seen as bounds for the upper tail of the cumulative distribution function for ''k'' ≥ ''np''.
 
For ''k'' ≤ ''np'', upper bounds can be derived for the lower tail of the cumulative distribution function <math>F(k;n,p) = \Pr(X \le k)</math>, the probability that there are at most ''k'' successes. Since <math>\Pr(X \ge k) = F(n-k;n,1-p) </math>, these bounds can also be seen as bounds for the upper tail of the cumulative distribution function for ''k'' ≥ ''np''.
   −
对于''k''≤''np'',可以得出累积分布函数左尾的上界<math>F(k;n,p)=Pr(X \le k)</math>,即最多存在''k''次成功的概率。由于<math>/Pr(X \ge k) = F(n-k;n,1-p) </math>,这些界限也可以看作是''k''≥''np''的累积分布函数右尾的边界。
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对于''k''≤''np'',可以得出累积分布函数左尾的上界<math>F(k;n,p)=Pr(X \le k)</math>,即最多存在''k''次成功的概率。由于<math>Pr(X \ge k) = F(n-k;n,1-p) </math>,这些界限也可以看作是''k''≥''np''的累积分布函数右尾的边界。
    
  F(k;n,\tfrac{1}{2}) \geq \frac{1}{15} \exp\left(- 16n \left(\frac{1}{2} -\frac{k}{n}\right)^2\right). \!
 
  F(k;n,\tfrac{1}{2}) \geq \frac{1}{15} \exp\left(- 16n \left(\frac{1}{2} -\frac{k}{n}\right)^2\right). \!
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: <math> \widehat{p\,} \pm z \sqrt{ \frac{ \widehat{p\,} ( 1 -\widehat{p\,} )}{ n } } .</math>
 
: <math> \widehat{p\,} \pm z \sqrt{ \frac{ \widehat{p\,} ( 1 -\widehat{p\,} )}{ n } } .</math>
   −
  <math>\frac{
+
  <math>\frac{}\widehat{p\,} + \frac{z^2}{2n} + z</math>
    +
: A [[continuity correction]] of 0.5/''n'' may be added. {{clarify|date=July 2012}};
   −
    \widehat{p\,} + \frac{z^2}{2n} + z}</math>
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可以添加一个0.5/''n''连续调整。(2012年7月更新)
   −
: A [[continuity correction]] of 0.5/''n'' may be added.{{clarify|date=July 2012}}
+
<math>    \sqrt{\frac{\widehat{p\,}(1 - \widehat{p\,})}{n} </math>
    \sqrt{
      +
==== Agresti–Coull method ====
   −
        \frac{\widehat{p\,}(1 - \widehat{p\,})}{n} +
+
阿格里斯蒂-库尔方法 Agresti–Coull method
   −
==== Agresti–Coull method ====
+
<math>        \frac{z^2}{4 n^2}</math>
 
  −
        \frac{z^2}{4 n^2}
      
<ref name=Agresti1988>{{Citation |last1=Agresti |first1=Alan |last2=Coull |first2=Brent A. |date=May 1998 |title=Approximate is better than 'exact' for interval estimation of binomial proportions |url = http://www.stat.ufl.edu/~aa/articles/agresti_coull_1998.pdf |journal=The American Statistician |volume=52 |issue=2 |pages=119–126 |accessdate=2015-01-05 |doi=10.2307/2685469 |jstor=2685469 }}</ref>
 
<ref name=Agresti1988>{{Citation |last1=Agresti |first1=Alan |last2=Coull |first2=Brent A. |date=May 1998 |title=Approximate is better than 'exact' for interval estimation of binomial proportions |url = http://www.stat.ufl.edu/~aa/articles/agresti_coull_1998.pdf |journal=The American Statistician |volume=52 |issue=2 |pages=119–126 |accessdate=2015-01-05 |doi=10.2307/2685469 |jstor=2685469 }}</ref>
 
+
{
    }
  −
 
  −
 
  −
}{
      
:: <math> \tilde{p} \pm z \sqrt{ \frac{ \tilde{p} ( 1 - \tilde{p} )}{ n + z^2 } } .</math>
 
:: <math> \tilde{p} \pm z \sqrt{ \frac{ \tilde{p} ( 1 - \tilde{p} )}{ n + z^2 } } .</math>
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Then log(T) is approximately normally distributed with mean log(p1/p2) and variance ((1/p1)&nbsp;−&nbsp;1)/n&nbsp;+&nbsp;((1/p2)&nbsp;−&nbsp;1)/m.
 
Then log(T) is approximately normally distributed with mean log(p1/p2) and variance ((1/p1)&nbsp;−&nbsp;1)/n&nbsp;+&nbsp;((1/p2)&nbsp;−&nbsp;1)/m.
   −
然后log(T)近似服从正态分布,均值为log(p1/p2)和方差为((1/p1)&nbsp;−&nbsp;1)/n&nbsp;+&nbsp;((1/p2)&nbsp;−&nbsp;1)/m。
+
然后log(T)近似服从正态分布,均值为log(p1/p2)和方差为<math>((1/p1)&nbsp;−&nbsp;1)/n&nbsp;+&nbsp;((1/p2)&nbsp;−&nbsp;1)/m</math>。
    
: <math>\sin^2 \left(\arcsin \left(\sqrt{\widehat{p\,}}\right) \pm \frac{z}{2\sqrt{n}} \right).</math>
 
: <math>\sin^2 \left(\arcsin \left(\sqrt{\widehat{p\,}}\right) \pm \frac{z}{2\sqrt{n}} \right).</math>
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* Firstly, ''z''<sub>''x''</sub> has a slightly different interpretation in the formula below: it has its ordinary meaning of 'the ''x''th quantile of the standard normal distribution', rather than being a shorthand for 'the (1&nbsp;−&nbsp;''x'')-th quantile'.
 
* Firstly, ''z''<sub>''x''</sub> has a slightly different interpretation in the formula below: it has its ordinary meaning of 'the ''x''th quantile of the standard normal distribution', rather than being a shorthand for 'the (1&nbsp;−&nbsp;''x'')-th quantile'.
   −
首先,''z''<sub>''x''</sub>在下式中的解释略有不同:它的普通含义是标准正态分布''x-th''的分位数,而不是(1&nbsp;−&nbsp;''x'')-th分位数的简写。
+
首先,''z''<sub>''x''</sub>在下式中的解释略有不同:它的普通含义是标准正态分布''x-th''的分位数,而不是(1&nbsp;−&nbsp;''x'')-''th''分位数的简写。
       
* Secondly, this formula does not use a plus-minus to define the two bounds. Instead, one may use <math>z = z_{\alpha / 2}</math> to get the lower bound, or use <math>z = z_{1 - \alpha/2}</math> to get the upper bound. For example: for a 95% confidence level the error <math>\alpha</math>&nbsp;=&nbsp;0.05, so one gets the lower bound by using <math>z = z_{\alpha/2} = z_{0.025} = - 1.96</math>, and one gets the upper bound by using <math>z = z_{1 - \alpha/2} = z_{0.975} = 1.96</math>.
 
* Secondly, this formula does not use a plus-minus to define the two bounds. Instead, one may use <math>z = z_{\alpha / 2}</math> to get the lower bound, or use <math>z = z_{1 - \alpha/2}</math> to get the upper bound. For example: for a 95% confidence level the error <math>\alpha</math>&nbsp;=&nbsp;0.05, so one gets the lower bound by using <math>z = z_{\alpha/2} = z_{0.025} = - 1.96</math>, and one gets the upper bound by using <math>z = z_{1 - \alpha/2} = z_{0.975} = 1.96</math>.
   −
*其次,这个公式没有使用加减法来定义两个界限。相反,我们可以使用<math>z = z_{/alpha / 2}</math>得到下限,或者使用<math>z = z_{1 - \alpha/2}</math>得到上限。例如:对于95%的置信度,误差为<math>/alpha</math>&nbsp;=&nbsp;0.05,所以用<math>z = z_{/alpha/2} = z_{0.025} = - 1.96</math>得到下限,用<math>z = z_{1 - \alpha/2} = z_{0.975} = 1.96</math>得到上限。
+
*其次,这个公式没有使用加减法来定义两个界限。相反,我们可以使用<math>z = z_{/alpha / 2}</math>得到下限,或者使用<math>z = z_{1 - \alpha/2}</math>得到上限。例如:对于95%的置信度,误差为<math>alpha</math>&nbsp;=&nbsp;0.05,所以用<math>z = z_{/alpha/2} = z_{0.025} = - 1.96</math>得到下限,用<math>z = z_{1 - \alpha/2} = z_{0.975} = 1.96</math>得到上限。
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<math>\begin{align}
+
<math>\begin{align}</math>
    
:: <math>\frac{}
 
:: <math>\frac{}
 +
<math>\Pr[Y = m] &= \sum_{k = m}^{n} \Pr[Y = m \mid X = k] \Pr[X = k] \\[2pt]</math>
   −
   \Pr[Y = m] &= \sum_{k = m}^{n} \Pr[Y = m \mid X = k] \Pr[X = k] \\[2pt]
+
<math>   \widehat{p\,} + \frac{z^2}{2n} + z</math>
 
  −
    \widehat{p\,} + \frac{z^2}{2n} + z
     −
  &= \sum_{k=m}^n \binom{n}{k} \binom{k}{m} p^k q^m (1-p)^{n-k} (1-q)^{k-m}
+
<math>  &= \sum_{k=m}^n \binom{n}{k} \binom{k}{m} p^k q^m (1-p)^{n-k} (1-q)^{k-m}</math>
   −
     \sqrt{
+
     \sqrt{}
   −
\end{align}</math>
+
<math> \end{align}</math>
    
<math>\frac{\widehat{p\,}(1 - \widehat{p\,})}{n} </math>
 
<math>\frac{\widehat{p\,}(1 - \widehat{p\,})}{n} </math>
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由于<math>\tbinom{n}{k} \tbinom{k}{m} = \tbinom{n}{m} \tbinom{n-m}{k-m}</math>,上述方程可表示为
 
由于<math>\tbinom{n}{k} \tbinom{k}{m} = \tbinom{n}{m} \tbinom{n-m}{k-m}</math>,上述方程可表示为
   −
<math>        \frac{z^2}{4 n^2}
+
<math>        \frac{z^2}{4 n^2}</math>
   −
\Pr[Y = m] = \sum_{k=m}^{n} \binom{n}{m} \binom{n-m}{k-m} p^k q^m (1-p)^{n-k} (1-q)^{k-m} </math>
+
<math> \Pr[Y = m] = \sum_{k=m}^{n} \binom{n}{m} \binom{n-m}{k-m} p^k q^m (1-p)^{n-k} (1-q)^{k-m} </math>
    
Factoring  p^k = p^m p^{k-m}  and pulling all the terms that don't depend on  k  out of the sum now yields
 
Factoring  p^k = p^m p^{k-m}  and pulling all the terms that don't depend on  k  out of the sum now yields
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}{
 
}{
   −
<math>\begin{align}
+
<math>\begin{align}</math>
   −
    1 + \frac{z^2}{n}
+
<math>    1 + \frac{z^2}{n}</math>
   −
  \Pr[Y = m] &= \binom{n}{m} p^m q^m \left( \sum_{k=m}^n \binom{n-m}{k-m} p^{k-m} (1-p)^{n-k} (1-q)^{k-m} \right) \\[2pt]
+
<math>  \Pr[Y = m] &= \binom{n}{m} p^m q^m \left( \sum_{k=m}^n \binom{n-m}{k-m} p^{k-m} (1-p)^{n-k} (1-q)^{k-m} \right) \\[2pt]}</math><ref>{{cite book
   −
}</math><ref>{{cite book}}
+
<math>   &= \binom{n}{m} (pq)^m \left( \sum_{k=m}^n \binom{n-m}{k-m} \left(p(1-q)\right)^{k-m} (1-p)^{n-k}  \right)</math>
 
  −
  &= \binom{n}{m} (pq)^m \left( \sum_{k=m}^n \binom{n-m}{k-m} \left(p(1-q)\right)^{k-m} (1-p)^{n-k}  \right)
      
| chapter = Confidence intervals
 
| chapter = Confidence intervals
   −
\end{align}</math>
      
| chapter-url = http://www.itl.nist.gov/div898/handbook/prc/section2/prc241.htm
 
| chapter-url = http://www.itl.nist.gov/div898/handbook/prc/section2/prc241.htm
    
After substituting  i = k - m  in the expression above, we get
 
After substituting  i = k - m  in the expression above, we get
  −
在上面的表达式中用 i = k-m 代替后,我们得到了
      
| title = Engineering Statistics Handbook
 
| title = Engineering Statistics Handbook
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Notice that the sum (in the parentheses) above equals  (p - pq + 1 - p)^{n-m}  by the binomial theorem. Substituting this in finally yields
 
Notice that the sum (in the parentheses) above equals  (p - pq + 1 - p)^{n-m}  by the binomial theorem. Substituting this in finally yields
  −
注意,上面的和(在括号中)等于(p-pq + 1-p) ^ { n-m }二项式定理。最终将其替换为
      
| year = 2012
 
| year = 2012
  −
<math>\begin{align}
      
1.1.1.2.2.2.2.2.2.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.4.3
 
1.1.1.2.2.2.2.2.2.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.3.4.3
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| access-date = 2017-07-23
 
| access-date = 2017-07-23
   −
  \Pr[Y=m] &=  \binom{n}{m} (pq)^m (p - pq + 1 - p)^{n-m}\\[4pt]
+
<math>  \Pr[Y=m] &=  \binom{n}{m} (pq)^m (p - pq + 1 - p)^{n-m}\\[4pt]</math>
    
}}</ref>
 
}}</ref>
   −
  &= \binom{n}{m} (pq)^m (1-pq)^{n-m}
+
<math>  &= \binom{n}{m} (pq)^m (1-pq)^{n-m}</math>  
 
  −
 
  −
 
  −
\end{align}</math>  
      
==== Comparison ====
 
==== Comparison ====
第1,079行: 第1,060行:       −
:<math>\begin{align}
+
:<math>\operatorname P(Z=k) &= \sum_{i=0}^k\left[\binom{n}i p^i (1-p)^{n-i}\right]\left[\binom{m}{k-i} p^{k-i} (1-p)^{m-k+i}\right]\\</math>
 
  −
  \operatorname P(Z=k) &= \sum_{i=0}^k\left[\binom{n}i p^i (1-p)^{n-i}\right]\left[\binom{m}{k-i} p^{k-i} (1-p)^{m-k+i}\right]\\
      
Binomial [[probability mass function and normal probability density function approximation for n&nbsp;=&nbsp;6 and p&nbsp;=&nbsp;0.5]]
 
Binomial [[probability mass function and normal probability density function approximation for n&nbsp;=&nbsp;6 and p&nbsp;=&nbsp;0.5]]
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二项式n&nbsp;=&nbsp;6 and p&nbsp;=&nbsp;0.5的概率质量函数和正态概率密度函数近似
 
二项式n&nbsp;=&nbsp;6 and p&nbsp;=&nbsp;0.5的概率质量函数和正态概率密度函数近似
   −
                      &= \binom{n+m}k p^k (1-p)^{n+m-k}
+
                      <math> &= \binom{n+m}k p^k (1-p)^{n+m-k}</math>
   −
\end{align}</math>
      
If n is large enough, then the skew of the distribution is not too great. In this case a reasonable approximation to B(n,&nbsp;p) is given by the normal distribution
 
If n is large enough, then the skew of the distribution is not too great. In this case a reasonable approximation to B(n,&nbsp;p) is given by the normal distribution
第1,173行: 第1,151行:  
由于<math> X \sim B(n, p) </math>和<math> Y \sim B(X, q) </math>,由全概率公式,
 
由于<math> X \sim B(n, p) </math>和<math> Y \sim B(X, q) </math>,由全概率公式,
   −
:<math>\begin{align}
+
:<math>\Pr[Y = m] &= \sum_{k = m}^{n} \Pr[Y = m \mid X = k] \Pr[X = k] \\[2pt]</math>
 
  −
  \Pr[Y = m] &= \sum_{k = m}^{n} \Pr[Y = m \mid X = k] \Pr[X = k] \\[2pt]
     −
P(p;\alpha,\beta) = \frac{p^{\alpha-1}(1-p)^{\beta-1}}{\mathrm{B}(\alpha,\beta)}.
+
<math>P(p;\alpha,\beta) = \frac{p^{\alpha-1}(1-p)^{\beta-1}}{\mathrm{B}(\alpha,\beta)}.</math>
   −
P (p; alpha,beta) = frac { p ^ { alpha-1}(1-p) ^ { beta-1}{ mathrm { b }(alpha,beta)}}.
+
<math>P (p; alpha,beta) = frac { p ^ { alpha-1}(1-p) ^ { beta-1}{ mathrm { b }(alpha,beta)}}.
   −
   &= \sum_{k=m}^n \binom{n}{k} \binom{k}{m} p^k q^m (1-p)^{n-k} (1-q)^{k-m}
+
   &= \sum_{k=m}^n \binom{n}{k} \binom{k}{m} p^k q^m (1-p)^{n-k} (1-q)^{k-m}</math>
    
Given a uniform prior, the posterior distribution for the probability of success  given  independent events with  observed successes is a beta distribution.
 
Given a uniform prior, the posterior distribution for the probability of success  given  independent events with  observed successes is a beta distribution.
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给定一个一致性先验,给定观察到成功结果的独立事件成功概率的后验分布是一个beta分布。
 
给定一个一致性先验,给定观察到成功结果的独立事件成功概率的后验分布是一个beta分布。
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\end{align}</math>
      
Since <math>\tbinom{n}{k} \tbinom{k}{m} = \tbinom{n}{m} \tbinom{n-m}{k-m},</math> the equation above can be expressed as
 
Since <math>\tbinom{n}{k} \tbinom{k}{m} = \tbinom{n}{m} \tbinom{n-m}{k-m},</math> the equation above can be expressed as
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<font color="#ff8000">边缘分布 marginal distribution </font>是二项分布较完善的随机数产生方法。
 
<font color="#ff8000">边缘分布 marginal distribution </font>是二项分布较完善的随机数产生方法。
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:<math>\begin{align}
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:<math>\Pr[Y = m] &= \binom{n}{m} p^m q^m \left( \sum_{k=m}^n \binom{n-m}{k-m} p^{k-m} (1-p)^{n-k} (1-q)^{k-m} \right) \\[2pt]</math>
 
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  \Pr[Y = m] &= \binom{n}{m} p^m q^m \left( \sum_{k=m}^n \binom{n-m}{k-m} p^{k-m} (1-p)^{n-k} (1-q)^{k-m} \right) \\[2pt]
      
One way to generate random samples from a binomial distribution is to use an inversion algorithm. To do so, one must calculate the probability that  for all values  from  through . (These probabilities should sum to a value close to one, in order to encompass the entire sample space.) Then by using a pseudorandom number generator to generate samples uniformly between 0 and 1, one can transform the calculated samples into discrete numbers by using the probabilities calculated in the first step.
 
One way to generate random samples from a binomial distribution is to use an inversion algorithm. To do so, one must calculate the probability that  for all values  from  through . (These probabilities should sum to a value close to one, in order to encompass the entire sample space.) Then by using a pseudorandom number generator to generate samples uniformly between 0 and 1, one can transform the calculated samples into discrete numbers by using the probabilities calculated in the first step.
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The binomial distribution is a special case of the [[Poisson binomial distribution]], or [[general binomial distribution]], which is the distribution of a sum of ''n'' independent non-identical [[Bernoulli trials]] B(''p<sub>i</sub>'').<ref>
 
The binomial distribution is a special case of the [[Poisson binomial distribution]], or [[general binomial distribution]], which is the distribution of a sum of ''n'' independent non-identical [[Bernoulli trials]] B(''p<sub>i</sub>'').<ref>
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二项分布是泊松二项分布或广义二项分布的特例,它是''n''个独立的不相同的伯努利试验之和的分布。B(''p<sub>i</sub>'') <ref>
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{{Cite journal
 
{{Cite journal
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}}
 
}}
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</ref>
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</ref>
+
二项分布是泊松二项分布或广义二项分布的特例,它是''n''个独立的不相同的伯努利试验之和的分布。B(''p<sub>i</sub>'') <ref>{{Cite journal | volume = 3 | issue = 2 | pages = 295–312 | last = Wang | first = Y. H. | title = On the number of successes in independent trials | journal = Statistica Sinica | year = 1993 | url = http://www3.stat.sinica.edu.tw/statistica/oldpdf/A3n23.pdf | url-status = dead | archiveurl = https://web.archive.org/web/20160303182353/http://www3.stat.sinica.edu.tw/statistica/oldpdf/A3n23.pdf | archivedate = 2016-03-03}}</ref>
     
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