作者a5170040 (小豬)
看板Statistics
標題[問題] 一題清大考題
時間Sat Jan 12 21:30:30 2008
Toss a fair coin and take a step of size c to the right if head shows,
to the left if tail shows. At the nth toss ,the poisition is a random
variable Xn taking the values mc ,where m=n,n-2,...,-n
a.Find P(Xn=mc)
b.Show that for large n
2
1 -m / 2n
P(Xn=mc)～ ----------- e
√(n*pi/2)
c.Find the probability that at the 50th step,X50 will exceed 6c.
麻煩各位了!實在不太清楚怎麼下手耶...
可以給個Hint也好!
謝謝!感激不盡!
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1F：推 hi123:請問m的範圍有打錯嗎? 01/14 22:08