สำหรับ ให้ จาก law of total expectation เราได้ว่า
ErrorToo many requests (f061ab2) If you report this error to the Wikimedia System Administrators, please include the details below.
![{\displaystyle \Pr(a_{i}<i)E[X_{i}\ |\ a_{i}<i]+\Pr(a_{i}=i)E[X_{i}\ |\ a_{i}=i]+\Pr(a_{i}>i)E[X_{i}\ |\ a_{i}>i]\,}](https://wikimedia.org/api/rest_v1/media/math/render/svg/406236064de1e0fa6d93713b554e307ab2a74d99) |
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ErrorToo many requests (f061ab2) If you report this error to the Wikimedia System Administrators, please include the details below.
![{\displaystyle {\frac {1}{2n}}[(i-1)i+(n-i)(n-i+1)]\,}](https://wikimedia.org/api/rest_v1/media/math/render/svg/f6ccf46e0bdaba00889c3b325cbd0c6800b7e7e8) |
ฉะนั้น
ErrorToo many requests (f061ab2) If you report this error to the Wikimedia System Administrators, please include the details below.
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ErrorToo many requests (f061ab2) If you report this error to the Wikimedia System Administrators, please include the details below.
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