Chi squared help !

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  1. Calllu-m's Avatar
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    Chi squared help !
    I'm doing maths coursework in which I need to incorperate a chi squared test and a step by step guide of how i did. I have no idea how to do it with my data sets. Basically I'm trying to determine if height affects tries scored in a rugby season and i have the height of 35 rugby players with the tries they scored per season. How would i show this in tables for my step by step method. Sorry if this is confusing to read I'm just in a rush!
  2. Calllu-m's Avatar
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    Re: Chi squared help !
    Anyone ?
  3. BabyMaths's Avatar
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    Re: Chi squared help !
    (Original post by Calllu-m)
    I have no idea how to do it with my data sets.
    Well what do you know about it?

    It would be a pain to explain the whole thing. There are easy to find worked examples out there.
  4. Calllu-m's Avatar
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    Re: Chi squared help !
    (Original post by BabyMaths)
    Well what do you know about it?

    It would be a pain to explain the whole thing. There are easy to find worked examples out there.
    I know how to do a chi squared test, but not with my data sets. Basically I have heights and then scores next to them. I'm trying to work out how I could do a chi squared for them, as the worked examples are a lot different.
  5. BabyMaths's Avatar
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    Re: Chi squared help !
    Put your heights into categories.
  6. Calllu-m's Avatar
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    Re: Chi squared help !
    (Original post by BabyMaths)
    Put your heights into categories.
    Did that but it still didn't work. I am competent with maths and wouldn't ask for help if I didn't need it, so i've covered most bases.
  7. BabyMaths's Avatar
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    Re: Chi squared help !
    Post your working.
  8. Calllu-m's Avatar
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    Re: Chi squared help !
    Observed
    Height Tries scored
    160-169 27 27
    170-179 59 59
    180-189 52 52
    190-199 96 96
    234





    Expected
    160-169 27 27
    170-179 59 59
    180-189 52 52
    190-199 96 96
    234 234


    because there's only tries scored per season the expected/observed are the same.


    (Original post by BabyMaths)
    Post your working.
  9. BabyMaths's Avatar
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    Re: Chi squared help !
    (Original post by Calllu-m)
    Observed
    Height Tries scored
    160-169 27 27
    170-179 59 59
    180-189 52 52
    190-199 96 96
    234





    Expected
    160-169 27 27
    170-179 59 59
    180-189 52 52
    190-199 96 96
    234 234


    because there's only tries scored per season the expected/observed are the same.
    How many players do you have in each height category?

    If the number of tries scored is not related to the height of the player then you would expect the number of tries in each category to be proportional to the number of players in each category.
  10. Calllu-m's Avatar
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    Re: Chi squared help !
    (Original post by BabyMaths)
    How many players do you have in each height category?

    If the number of tries scored is not related to the height of the player then you would expect the number of tries in each category to be proportional to the number of players in each category.
    35 players overall, varied numbers. 12, 10, 6, and 7. Number of tries is related. I couldn't get an equal number of heights.
  11. BabyMaths's Avatar
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    Re: Chi squared help !
    There were 234 tries.

    Expected values are

    \frac{12}{35}\times 234,

    \frac{10}{35}\times 234

    etc..
    Last edited by BabyMaths; 31-07-2012 at 21:42. Reason: corrected typo.
  12. Calllu-m's Avatar
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    Re: Chi squared help !
    (Original post by BabyMaths)
    There were 234 tries.

    Expected values are

    \frac{12}{35}\times 234,

    \frac{10}{35}\times 234

    etc..
    Thank you
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