ABX P Value, Correct Equation 
ABX P Value, Correct Equation 
Sep 22 2004, 12:14
Post
#1


Group: Members Posts: 1018 Joined: 27September 03 From: Cape Town Member No.: 9042 
I definately remember reading a discussion on the correct calculation of the ABX pvalue (probability you were guessing) a while back but a couple of searches and a read through the FAQ were unhelpful. From my limited stats knowledge (half a semester on probability) I came up with (for p correct from n trials) nCk*(0.5)^n*(0.5)^(nk) which simplifies to nCk/2^n. This doesn't seem correct to me.
What is the correct equation for working this out?  Simulate your radar: http://www.brooker.co.za/fers/



Sep 22 2004, 21:02
Post
#2


Group: Developer Posts: 432 Joined: 22February 04 From: San Diego, CA Member No.: 12180 
I don't know if there's an easier mathematical equation for it, but this one works:
n=number of trials k=number correct q=temp variable sum( q=0 to nk : (nCq) / (2^n)) For n=5 and k=4, this gives 1/32 + 5/32 = 3/16 ~ 0.1875 [edit: deleted quote] This post has been edited by Omion: Sep 22 2004, 21:03  "We demand rigidly defined areas of doubt and uncertainty!"  Vroomfondel, H2G2



Sep 22 2004, 22:05
Post
#3


Group: Members Posts: 2526 Joined: 25July 02 From: South Korea Member No.: 2782 
 http://blacksun.ivyro.net/vorbis/vorbisfaq.htm



Sep 23 2004, 07:40
Post
#4


Group: Members Posts: 1018 Joined: 27September 03 From: Cape Town Member No.: 9042 
Thanks Omion and kjoonlee, that's just what I was looking for.
 Simulate your radar: http://www.brooker.co.za/fers/



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