作者PrettyFace (圣洁之水)
看板Statistics
标题[问题] 94中正统计
时间Sun Jun 7 18:04:47 2009
想请问一题考古题
(94中正统计)
A box contain 4 red balls and 6 blue balls. Two balls are drawn at random and,
without seeing their colors, are thrown out.
If a third ball is drawn randomly and found to be a red ball,what's the
probability that the previous two balls are blue?
这题可以用条件机率去算吗? 算出来的答案为5/12 对吗?
那有其他的算法吗? 譬如说服从某种分布(超几何分布?)
--
※ 发信站: 批踢踢实业坊(ptt.cc)
◆ From: 192.192.167.51
※ 编辑: PrettyFace 来自: 192.192.167.51 (06/07 18:05)
※ 编辑: PrettyFace 来自: 192.192.167.51 (06/07 18:07)
1F：推 taichi53719:我算的答案跟你一样，如果硬要配各分配的话二项应该是 06/08 12:56
2F：→ taichi53719:比较适合的 06/08 12:56