siblings with same birthdaygreenspun.com : LUSENET : Birth Order : One Thread
I would like to know what the odds are of having two siblings in the same family with the same birth date. It happened to two of my children and I found that to be quite remarkable. Perhaps it isn't as remarkable as I think and I am interested in knowing any statistics on something like this.
-- jane nelsen (email@example.com), December 31, 2001
The odds would be less than 364 to 1 (i.e. a greater than 1/365 chance of the second born with the same birthday as the firstborn). With more than 2 children, the probability increases since there is more than 1 pairwise relationship.
-- Jon Miles (firstname.lastname@example.org), January 02, 2002.