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    (Original post by economicss)
    Yeah
    then you're pretty much ready for the exam! Give S3 a rest for now and come back to it a week or two and redo some past papers. if you can get your hands on the old book it might be helpful as well.
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    (Original post by aymanzayedmannan)
    then you're pretty much ready for the exam! Give S3 a rest for now and come back to it a week or two and redo some past papers. if you can get your hands on the old book it might be helpful as well.
    Thanks for the advice appreciate it
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    https://doc-00-70-docs.googleusercon...2pSWXVBZ2s2MlE <<<<< Question Paper - Page 9

    q7 part b don't get it at all - I don't see where one of the numbers comes from/

    https://doc-0o-70-docs.googleusercon...0owajlZaGxnZjA <<<<< MARKSCHEME - Page 8
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    (Original post by tazza ma razza)
    https://doc-00-70-docs.googleusercon...2pSWXVBZ2s2MlE <<<<< Question Paper - Page 9

    q7 part b don't get it at all - I don't see where one of the numbers comes from/

    https://doc-0o-70-docs.googleusercon...0owajlZaGxnZjA <<<<< MARKSCHEME - Page 8
    The document won't open? Could you send a picture or the name of the paper please
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    Hi, does anyone know please whether a question like 14b on here http://madasmaths.com/archive/maths_..._variables.pdf is on spec? Since it involves continuity corrections and combining different distributions which I haven't seen before? Thanks
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    (Original post by economicss)
    Hi, does anyone know please whether a question like 14b on here http://madasmaths.com/archive/maths_..._variables.pdf is on spec? Since it involves continuity corrections and combining different distributions which I haven't seen before? Thanks
    What are the chances, I did this question this morning! I wouldn't say it's not on spec - they are allowed to ask anything from C1-4 and S1 -3 and continuity corrections are on S2. But will something like this show up on an Edexcel S3 exam? I highly doubt it.
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    (Original post by economicss)
    The document won't open? Could you send a picture or the name of the paper please
    i think it is june 09 qn 7 i'll double check though
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    (Original post by economicss)
    The document won't open? Could you send a picture or the name of the paper please
    https://869d950bf149eefd5cd2652b4001...%20Edexcel.pdf

    7b i had a problem with - can normally (no pun intended) do these style but don't know why i got it wrong twice
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    (Original post by tazza ma razza)
    https://869d950bf149eefd5cd2652b4001...%20Edexcel.pdf

    7b i had a problem with - can normally (no pun intended) do these style but don't know why i got it wrong twice
    Probability of at least 0.90. Quick percentage point lookup tells us that means we need z = 1.6449 since we need to consider 5% at either tail of the distribution.

    Anyhow, we need a confidence width of 0.05 \times 2 = 0.1. You know that the width of an interval is given by 2\ \times z \times \frac{\sigma}{\sqrt{n}}

    Plugging in our values gets us 2 \times 1.6449 \times \frac{0.2}{\sqrt{n}} = 2 \times 0.05

    Immediately: \displaystyle 1.6449 \times \frac{0.2}{\sqrt{n}} = 0.05 \Rightarrow \sqrt{n} = \frac{1.6449 \times 0.2}{0.05}

    Then squaring and taking the ceiling gets us the home run.
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    (Original post by Zacken)
    Probability of at least 0.90. Quick percentage point lookup tells us that means we need z = 1.6449 since we need to consider 5% at either tail of the distribution.

    Anyhow, we need a confidence width of 0.05 \times 2 = 0.1. You know that the width of an interval is given by 2\ \times z \times \frac{\sigma}{\sqrt{n}}

    Plugging in our values gets us 2 \times 1.6449 \times \frac{0.2}{\sqrt{n}} = 2 \times 0.05

    Immediately: \displaystyle 1.6449 \times \frac{0.2}{\sqrt{n}} = 0.05 \Rightarrow \sqrt{n} = \frac{1.6449 \times 0.2}{0.05}

    Then squaring and taking the ceiling gets us the home run.
    Thanks so much i ended up with o.4 instead of 0.2 so i missed the opportunity to cancel (Y)
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    (Original post by tazza ma razza)
    Thanks so much
    No worries. Did you understand it?
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    (Original post by Zacken)
    No worries. Did you understand it?
    yup, i initially had issues with figuring out where the 0.2 came from as i kept getting 0.4 but yes, makes a lot more sense now
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    (Original post by Ayman!)
    What are the chances, I did this question this morning! I wouldn't say it's not on spec - they are allowed to ask anything from C1-4 and S1 -3 and continuity corrections are on S2. But will something like this show up on an Edexcel S3 exam? I highly doubt it.
    So that is what cc stood for lol. Continuity correction.


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    (Original post by tazza ma razza)
    yup, i initially had issues with figuring out where the 0.2 came from as i kept getting 0.4 but yes, makes a lot more sense now
    Awesome. :yep:
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    (Original post by physicsmaths)
    So that is what cc stood for lol. Continuity correction.


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    Haha, mate I realised that you never did S2 properly 'cause you needed something like 2 UMS in it to get the A*? :rofl: Didn't you have to actually learn that **** for S3 and S4?
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    (Original post by Ayman!)
    Haha, mate I realised that you never did S2 properly 'cause you needed something like 2 UMS in it to get the A*? :rofl: Didn't you have to actually learn that **** for S3 and S4?
    I havent even looked at S4. Only done Ch1 and Ch3 in S3. I learnt afew chapters of S2 really well cause we did it at the start of the year. When step kicked in i was like **** this.


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    (Original post by physicsmaths)
    I havent even looked at S4. Only done Ch1 and Ch3 in S3. I learnt afew chapters of S2 really well cause we did it at the start of the year. When step kicked in i was like **** this.


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    Aye, gotta meet the A-level part of your offer as well. Are you banking on mechanics for that A*?
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    (Original post by Ayman!)
    Aye, gotta meet the A-level part of your offer as well. Are you banking on mechanics for that A*?
    Banking on some switches from Maths and FM and yeh hoping to get
    290+/300 for M4/5 S3 so I need to get moving on S3. D1 is easy to learn which is great. Then probably try cram D2 and S4 and get a total of 80 -100 UMS. Lol.


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    (Original post by physicsmaths)
    Banking on some switches from Maths and FM and yeh hoping to get
    290+/300 for M4/5 S3 so I need to get moving on S3. D1 is easy to learn which is great. Then probably try cram D2 and S4 and get a total of 80 -100 UMS. Lol.


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    I love how you're so tactical with requirements. :rofl: This will probably be me if I manage to bag an A* in M3 and FP2 early - I'd half-arse S2 then.
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    Just to check, if one our expected frequencies came out to 5 exactly, this wouldn't be combined right, we only combine values less than 5?! Thanks :-)
 
 
 
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