birthday paradox, one by one
This article is originally published at https://xianblog.wordpress.com
The answer is straightforward,
as only the last person in can share a birthday with those already in. This sum equals 24.62. Since the “magic number” is 23, this may sound wrong but the median attached to the above distribution is truly 23. My R code is
q=rep(1,a<-366)/(b<-a-1) for(n in 3:a)q[n]=q[n]=q[n-1]*(1+1/(n-2)-(n-1)/b) sum(q[-1]*(2:a))
Please visit source website for post related comments.