作者penatnl (penatnl)
看板Statistics
标题[问题]一题期望值的问题
时间Sun Sep 14 14:34:16 2008
Suppose n balls are distributed at random into r boxes.
Let Xi=1 if box i is empty and =0 otherwise.
(1)compute E(Xi)
(2)For i=/=j(i不等於j) compute E(XiXj)
--
※ 发信站: 批踢踢实业坊(ptt.cc)
◆ From: 59.105.48.36