Login

Welcome, Guest. Please login or register.

November 08, 2025, 02:26:49 pm

Author Topic: Normal approximation  (Read 1752 times)  Share 

0 Members and 1 Guest are viewing this topic.

TrueTears

  • TT
  • Honorary Moderator
  • Great Wonder of ATAR Notes
  • *******
  • Posts: 16363
  • Respect: +667
Normal approximation
« on: October 04, 2009, 08:13:42 pm »
0
Saw this in a question somewhere... not sure what it meant so I did some research. I understand that it's an approximation for binomial distribution when the sample group is very large, so it's approximated to be the same as a normal distribution. but is there a formal prove of how this is so?
PhD @ MIT (Economics).

Interested in asset pricing, econometrics, and social choice theory.

Mao

  • CH41RMN
  • Honorary Moderator
  • Great Wonder of ATAR Notes
  • *******
  • Posts: 9181
  • Respect: +390
  • School: Kambrya College
  • School Grad Year: 2008
Re: Normal approximation
« Reply #1 on: October 04, 2009, 09:40:50 pm »
0
Saw this in a question somewhere... not sure what it meant so I did some research. I understand that it's an approximation for binomial distribution when the sample group is very large, so it's approximated to be the same as a normal distribution. but is there a formal prove of how this is so?

This is akin to asking for a formal proof of linear regression. :P

When dealing with statistics and things of that like, try not to be too accurate :)
Editor for ATARNotes Chemistry study guides.

VCE 2008 | Monash BSc (Chem., Appl. Math.) 2009-2011 | UoM BScHon (Chem.) 2012 | UoM PhD (Chem.) 2013-2015

EvangelionZeta

  • Quintessence of Dust
  • Honorary Moderator
  • ATAR Notes Superstar
  • *******
  • Posts: 2435
  • Respect: +288
Re: Normal approximation
« Reply #2 on: October 04, 2009, 09:48:02 pm »
0
Saw this in a question somewhere... not sure what it meant so I did some research. I understand that it's an approximation for binomial distribution when the sample group is very large, so it's approximated to be the same as a normal distribution. but is there a formal prove of how this is so?

This is akin to asking for a formal proof of linear regression. :P

When dealing with statistics and things of that like, try not to be too accurate :)

...wut?? o_o
---

Finished VCE in 2010 and now teaching professionally. For any inquiries, email me at [email protected].

TrueTears

  • TT
  • Honorary Moderator
  • Great Wonder of ATAR Notes
  • *******
  • Posts: 16363
  • Respect: +667
Re: Normal approximation
« Reply #3 on: October 04, 2009, 09:50:49 pm »
0
Saw this in a question somewhere... not sure what it meant so I did some research. I understand that it's an approximation for binomial distribution when the sample group is very large, so it's approximated to be the same as a normal distribution. but is there a formal prove of how this is so?

This is akin to asking for a formal proof of linear regression. :P

When dealing with statistics and things of that like, try not to be too accurate :)
lol, alright, thanks for that Mao.
PhD @ MIT (Economics).

Interested in asset pricing, econometrics, and social choice theory.

kamil9876

  • Victorian
  • Part of the furniture
  • *****
  • Posts: 1943
  • Respect: +109
Re: Normal approximation
« Reply #4 on: October 04, 2009, 10:16:25 pm »
0
I think it's a fair question to ask. Even the study of approximations like is still about precision, because you can precisely show that the approximation can be as good as you want it to be i.e for any for some large enough .

I guess his question is really akin to "what is normal distribution, is the definition of it at all tied to binomial? maybe do another argument to see if it is at all related to binomial?"

To be honest I don't know what the answer to that question is because statistics just sounds so boring and I've paid no attention to it at all. Maybe it will satisfy a bit of curiosity though :P




edit: I guess I just have a vague notion that any continous probability really just comes from discrete probability (u know, that histogram diagram, or that fun breaking the stick into three pieces question (from SUPER-HAPPY-FUN-MATHS time, didn't even use calculus there and just took the limit of a discrete case). It would seem very unnatural that some random function would fit something so natural like binomial, so it was probably made from the binomial, a bit of google found this:

"de Moivre developed the normal distribution as an approximation to the binomial distribution,"

http://mathworld.wolfram.com/NormalDistribution.html

« Last Edit: October 04, 2009, 10:24:11 pm by kamil9876 »
Voltaire: "There is an astonishing imagination even in the science of mathematics ... We repeat, there is far more imagination in the head of Archimedes than in that of Homer."