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    I read on another thread (link: http://www.thestudentroom.co.uk/show...949172&page=15) that if the mean is 50 and the coding is x/10 the mean becomes 0.5- but is that true?
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    (Original post by tazza ma razza)
    mate - this has been asked countless times - I can't recollect there being an answer tho ahaha Have you checked the textbook?
    sorry I just got back from chemistry and do S1 straight away so havent check, that case was like an extra number added, but what if we code like v=x/1000, would it matter ??
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    (Original post by siamesedaffodil)
    Using a venn diagram..

    ...how would you work out P(A' U B) and P(A' U B'?? ? ?

    Thanks!!
    In addition to the reply from earlier, I would say use the addition rule:

    P(A u B) = P(A) + P(B) - P(A n B)

    It's often easier to visualise intersections rather than unions so use this if you're stuck.
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    (Original post by physicsamor)
    Good luck everyone I'm done for the day. Just try your best
    thanks good luck to you too!
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    (Original post by anndz3007)
    sorry I just got back from chemistry and do S1 straight away so havent check, that case was like an extra number added, but what if we code like v=x/1000, would it matter ??
    I'm so confused, because apparently they're all different for Sxx, Syy and Sxy
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    Can someone please list all the things that can be coded and explain effect of coding on each of these things?
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    (Original post by hogree)
    So, say you have 60 values. You want to work out the lower quartile. Do n/4 ---> 6/4 -----> 15. So you use the 15.5th value.
    Okay, but when I find the Q2, it's 60/4 which is 30, so I find the average of the 30th and 31st value?
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    (Original post by hogree)
    So, if you have a Coding where of say 2X+6, you ignore the +6. You multiply the Sxx by 4 (because that's 2^2), You multiply the Sxy by 2, and you don't multiply the Syy. That's what I saw from someone else. PMCC remains the same always.


    Yes, that would be an example of when you would use that method.
    So Sxx = multiply by n^2
    Sxy = multiply by n
    Syy = no effect

    Also are you 100% certain because I cant find much regarding this?
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    (Original post by hogree)
    So, if you have a Coding where of say 2X+6, you ignore the +6. You multiply the Sxx by 4 (because that's 2^2), You multiply the Sxy by 2, and you don't multiply the Syy. That's what I saw from someone else. PMCC remains the same always.


    Yes, that would be an example of when you would use that method.
    so like if you got x=2a+6, Sxx= 4 Saa, y=4b+1, Syy= 16 Sbb , and Sxy= (2x4=8) Sab ?? just checked it in one example and it didnt turn out right
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    Anyone got any predictions for tommorw??
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    (Original post by Mina_)
    So Sxx = multiply by n^2Sxy = multiply by nSyy = no effectAlso are you 100% certain because I cant find much regarding this?
    I cannot claim I am 100% certain. But I have seen a couple of people say this. Is there an example Question anywhere?
    (Original post by Uberphuq)
    Okay, but when I find the Q2, it's 60/4 which is 30, so I find the average of the 30th and 31st value?
    That's exactly right. An example of this being used in Question 2 of Jan 2008.

    (Original post by anndz3007)
    so like if you got x=2a+6, Sxx= 4 Saa, y=4b+1, Syy= 16 Sbb , and Sxy= (2x4=8) Sab ?? just checked it in one example and it didnt turn out right
    I think that is right. Could I have a look at the example?
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    (Original post by hogree)
    I cannot claim I am 100% certain. But I have seen a couple of people say this. Is there an example Question anywhere?That's exactly right. An example of this being used in Question 2 of Jan 2008.



    I think that is right. Could I have a look at the example?
    https://1a388b28f5ce9318f837a64962fc...%20Edexcel.pdf

    question 2, if you try to find d= Svs/Sss, you would not get the value as shown ??

    Edit: It actually works, sorry its just me messing with Sxx Sxy value
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    Can you use a black rollergel pen?


    Posted from TSR Mobile
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    (Original post by Mina_)
    So Sxx = multiply by n^2
    Sxy = multiply by n
    Syy = no effect

    Also are you 100% certain because I cant find much regarding this?

    so like if you got x=2a+6, Sxx= 4 Saa, y=4b+1, Syy= 16 Sbb , and Sxy= (2x4=8) Sab

    Checked and it work, if only x is coded, Syy does not change, if both coded, they both would change
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    [QUOTE=jessyjellytot14;65785699]Can you use a black rollergel pen?

    It says no gel pens on the exam so i highly doubt it. I use the Uni-ball Eye ink pens as the flow similar to gel pens
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    (Original post by SweetChilliCake)
    y=0.746+0.102x
    Also how do you do the last part of that question. I never understand them
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    (Original post by anndz3007)
    so like if you got x=2a+6, Sxx= 4 Saa, y=4b+1, Syy= 16 Sbb , and Sxy= (2x4=8) Sab

    Checked and it work, if only x is coded, Syy does not change, if both coded, they both would change
    Sorry but what are you on about
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    (Original post by anndz3007)
    https://1a388b28f5ce9318f837a64962fc...%20Edexcel.pdf

    question 2, if you try to find d= Svs/Sss, you would not get the value as shown ??

    Edit: It actually works, sorry its just me messing with Sxx Sxy value
    Yup it works. That's definitely the way to Code Regression. Fab
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    (Original post by thelegend99)
    hogree
    whoops hogree if events are independent, does that meant they're linked (does one affect the other)? Saw an example with two children being late.
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    (Original post by Zacken)
    No problem.
    So i stalked your profile and saw you insured warwick over imperial. Why?
 
 
 
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