Turn on thread page Beta

S3: Goodness-of-fit test for normal distribution watch

    • Thread Starter
    Offline

    3
    ReputationRep:
    .cccccc
    • Thread Starter
    Offline

    3
    ReputationRep:
    bump
    Offline

    14
    ReputationRep:
    I don't think enough people do S3 for you to be able to get a good answer
    • Very Important Poster
    Offline

    21
    ReputationRep:
    Very Important Poster
    (Original post by Nikhilm)
    .cccccc
    What is your question?
    • Thread Starter
    Offline

    3
    ReputationRep:
    (Original post by SeanFM)
    What is your question?
    Hey,

    It was to do with how you lay out an answer for goodness-of-fit tests with normal distributions
    I know you have to extrapolate the class widths at the ends, e.g. if question says

    3-4
    4-5
    ...
    9-10

    You would do
    < 4
    4-5
    ...
    > 9

    But, on the june 2013 mark scheme they just left it in the first form, and also the book changes between both
    • Very Important Poster
    Offline

    21
    ReputationRep:
    Very Important Poster
    (Original post by Nikhilm)
    Hey,

    It was to do with how you lay out an answer for goodness-of-fit tests with normal distributions
    I know you have to extrapolate the class widths at the ends, e.g. if question says

    3-4
    4-5
    ...
    9-10

    You would do
    < 4
    4-5
    ...
    > 9

    But, on the june 2013 mark scheme they just left it in the first form, and also the book changes between both
    Okay, I've had a look at the 2013 paper.

    I would say that because time is continuous (whereas size is not) you don't need classes for continuous data (0-3, 3-5 etc suffices) but for something like sizes or number of cars, you need those classes.
    • Thread Starter
    Offline

    3
    ReputationRep:
    Yes! Quite possibly

    Also, by any chance do you know what 'underlying Normal distribution' is, and how it is different from just 'Normal distribution'?

    SeanFM
    • Very Important Poster
    Offline

    21
    ReputationRep:
    Very Important Poster
    (Original post by Nikhilm)
    Yes! Quite possibly

    Also, by any chance do you know what 'underlying Normal distribution' is, and how it is different from just 'Normal distribution'?

    SeanFM
    I don't know myself, but see this document, page 27.

    From what I understand, an underlying distribution is just what the actual distribution of the sample is. (In similar words, what distribution produces the sample value that we get). Whereas we usually are given sample values and have to work out an estimator (which isn't the underlying distribution) and use that as a distribution.

    Not of that much important in S3 as far as I'm aware.
    Offline

    14
    ReputationRep:
    (Original post by SeanFM)
    From what I understand, an underlying distribution is just what the actual distribution of the sample is. (In similar words, what distribution produces the sample value that we get).
    Just to be utterly nit-picky, the underlying distribution is the distribution of the population from which the sample is drawn. A big chunk of statistics involves inferring facts about the population distribution from a sample distribution.
    • Very Important Poster
    Offline

    21
    ReputationRep:
    Very Important Poster
    (Original post by Gregorius)
    Just to be utterly nit-picky, the underlying distribution is the distribution of the population from which the sample is drawn. A big chunk of statistics involves inferring facts about the population distribution from a sample distribution.
    I stand corrected. :hat2:
    • Thread Starter
    Offline

    3
    ReputationRep:
    (Original post by SeanFM)
    I stand corrected. :hat2:
    Thanks to you both!
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: March 30, 2016
The home of Results and Clearing

2,197

people online now

1,567,000

students helped last year

University open days

  1. Sheffield Hallam University
    City Campus Undergraduate
    Tue, 21 Aug '18
  2. Bournemouth University
    Clearing Open Day Undergraduate
    Wed, 22 Aug '18
  3. University of Buckingham
    Postgraduate Open Evening Postgraduate
    Thu, 23 Aug '18
Poll
A-level students - how do you feel about your results?
Useful resources

Make your revision easier

Maths

Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

Equations

How to use LaTex

Writing equations the easy way

Student revising

Study habits of A* students

Top tips from students who have already aced their exams

Study Planner

Create your own Study Planner

Never miss a deadline again

Polling station sign

Thinking about a maths degree?

Chat with other maths applicants

Can you help? Study help unanswered threads

Groups associated with this forum:

View associated groups

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.