The khanacademi has some interesting takes on explaining probability http://www.khanacademy.org/video/birthday-probability-problem?topic=probability
2012/2/14 Mike Day <[email protected]> > The recent Project Euler Problem number 371, > > http://projecteuler.net/problem=371 > > is related to the birthday problem. > Fellow J-ers might enjoy it. > > Mike > > On 15/01/2012 10:40 AM, Linda Alvord wrote: > > I have been reluctant to include the interesting fd created by Henry Rich > > and Ric Sherlock because I was unable to write the explicit version that > > produces their tacit version. I finally got it , so we now have another > fd. > > > > > > > > fdrs=:[: /:~ ({. , #)/.~ > > > > fdrs > > > > [: /:~ ({. , #)/.~ > > > > > > > > > > > > a=:3 2 3 3 1 3 4 1 1 2 > > > > fd=: 13 :'/:~(~.y),.#/.~y' > > > > fd > > > > [: /:~ ~. ,. #/.~ > > > > fd a > > > > 1 3 > > 2 2 > > 3 4 > > 4 1 > > > > > > > > From: Linda Alvord [mailto:[email protected]] > > Sent: Monday, January 09, 2012 10:45 AM > > To: 'Linda Alvord' > > Subject: Challenge 4 Bountiful Birthdays > > > > > > > > Chalenge 4 Bountiful Birthdays PLEASE DO NOT RESPOND UNTIL > 1/16/2012 > > 12 am EST > > > > > > > > For this challenge, as usual, do not use @ but you may use whatever > style > > and strategy you like to accomplish the task. > > > > > > > > The problem is to simulate the classic birthday problem. > > > > > > > > A single trial works this way. People enter a room one by one and > declare > > their birth date. Suppose the 29th person is the first person to match a > > birthday of someone in the room. The result of the first trial is 29. > > > > > > > > Repeat for 500 trials. > > > > > > > > If you use Kip's frequency distribution of the results you have lots of > > information. > > > > > > > > fd=:[: /:~ ~. ,. [: +/"1 ~. =/ ] > > > > > > > > But the mean gives a more concise summary of the data. So, the final > part > > of the problem is to obtain a list of 10 means of 500 trials and the > > mean of the means. > > > > > > > > 'til next week. > > > > > > > > Linda > > > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > -- Björn Helgason, Verkfræðingur Fornustekkum II 781 Hornafirði, t-póst: [email protected] gsm: +3546985532 twitter: @flugfiskur http://groups.google.com/group/J-Programming Tæknikunnátta höndlar hið flókna, sköpunargáfa er meistari einfaldleikans góður kennari getur stigið á tær án þess að glansinn fari af skónum /|_ .-----------------------------------. ,' .\ / | Með léttri lund verður | ,--' _,' | Dagurinn í dag | / / | Enn betri en gærdagurinn | ( -. | `-----------------------------------' | ) | (\_ _/) (`-. '--.) (='.'=) ♖♘♗♕♔♙ `. )----' (")_(") ☃☠ ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
