Hey! Sign in to get help with your study questionsNew here? Join for free to post

Chi Square Test

Announcements Posted on
AQA GCSE physics P1 unofficial mark scheme 05-05-2016
  1. Offline

    ReputationRep:
    Hi, I've been going over past exam problems, and I'm really struggling with Chi Square tests. I just don't really know whats going on.

    Specifically:
    Questions:



    Solutions:
    Click image for larger version. 

Name:	chisqs.jpg 
Views:	25 
Size:	115.6 KB 
ID:	145798

    So for part b) Is the number of degrees of freedom always n-1? I don't see what the answers mean by 3 entries, 1 constraint. Does that mean, if you were to put it in a table, there would be 3 items and 1 property they have? I.e 3 colours and a number attached to each?

    For part c), from what I remember, the probability of a type I error is equal to that of being in the rejection region. Does that apply here too?

    Part d) I get this, we want to test if the distribution is how they say it is. What I don't understand is why we are only performing a single tail test. This relates to part b) because in the answers he has written (in brackets) "one sided." I don't understand this at all, I knew how to picture it with a normal distribution. I'm finding it more difficult with this.

    In short, my main question is why are we performing a single tail test?

    Thanks for any help!
    Attached Thumbnails
    Click image for larger version. 

Name:	chisqq.jpg 
Views:	30 
Size:	91.8 KB 
ID:	145797  

Reply

Submit reply

Register

Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?
  2. this can't be left blank
    this email is already registered. Forgotten your password?
  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. Oops, you need to agree to our Ts&Cs to register
  2. Slide to join now Processing…

Updated: May 11, 2012
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

Today on TSR

AQA physics unit 1

Check the unofficial mark scheme

Poll
What date is the EU referendum on?
Useful resources

Make your revision easier

Maths

Maths Forum posting guidelines

Not sure where to post? Read here first

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
Study resources
Quick reply
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.