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    the question with water bottle and tap bottle
    The last part was like 46 boxes find the expectation so i did 46 times the answer i got in my last question anyone did the same?
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    Did anyone else get like 14000 for the variance or something like that, 145541 i know it had 14 in the start and it was a big number, not sure if thats right but it did seem like a massive number.
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    For the last part of the last question, I got so confused. Was it saying probability of hitting 3 in 6 throws? But if she hits 3 in the first 3, she stops.....so P(B*B*B in first 3) + (If 1B in first 3, 2 in next 3) + (2B in first 3, 1 in next 3)..

    e.g.
    BBB
    BNNBBN
    NBNBBN

    etc?
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    (Original post by Mahinder)
    the question with water bottle and tap bottle
    The last part was like 46 boxes find the expectation so i did 46 times the answer i got in my last question anyone did the same?
    48*0.8684 to get your answer.
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    (Original post by juniorx)
    oh **** looks like i made a mistake then
    aaargh i just calculated it now and it is 5.62x10-3. I'm not sure and can't remember if it i put 5.62 or 5.82 :confused:
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    (Original post by Blobar)
    Did anyone else get like 14000 for the variance or something like that, 145541 i know it had 14 in the start and it was a big number, not sure if thats right but it did seem like a massive number.
    I got that too! I wasn't sure if it was right....
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    (Original post by superxo2)
    For the last part of the last question, I got so confused. Was it saying probability of hitting 3 in 6 throws? But if she hits 3 in the first 3, she stops.....so P(B*B*B in first 3) + (If 1B in first 3, 2 in next 3) + (2B in first 3, 1 in next 3)..

    e.g.
    BBB
    BNNBBN
    NBNBBN

    etc?
    Nope sorry thats wrong because it said if she hits one in the first 3 throws then she just stops

    so

    BBB NNNBBB
    if it was BNNBBN she'd just stop after BNN
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    (Original post by Blobar)
    48*0.8684 to get your answer.
    yeh thats what i did
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    I almost did it wrong since I carried on from my 50 bags from the previous question so was doing P(X=0) 50C0 (0.9)^50, lucky I had time to go through all the question again and saw my mistake! Phew!
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    (Original post by Blobar)
    Did anyone else get like 14000 for the variance or something like that, 145541 i know it had 14 in the start and it was a big number, not sure if thats right but it did seem like a massive number.
    yesss i got a number that started with 1455... it was a big number!
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    how did u do your tree diagram and what did subsequently mean i think i got it all wrong haha
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    omfg i think i got the same as u for the var x
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    (Original post by Blobar)
    Nope sorry thats wrong because it said if she hits one in the first 3 throws then she just stops

    so

    BBB NNNBBB
    if it was BNNBBN she'd just stop after BNN
    oh!! I misread the question !!
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    (Original post by Blobar)
    Nope sorry thats wrong because it said if she hits one in the first 3 throws then she just stops

    so

    BBB NNNBBB
    if it was BNNBBN she'd just stop after BNN
    i nearly made that mistake and wasted 20 mins before i reread the question and actually understood it.
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    (Original post by superxo2)
    oh!! I misread the question !!
    Don't worry it was a toughie, when I first read it I wasnt even going to bother with it but I had like 20 minutes left lol so kinda forced myself into it.
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    (Original post by Attz_09)
    how did u do your tree diagram and what did subsequently mean i think i got it all wrong haha
    What mean? The questions were what is the probability she hits atleast one and what is the probability she gets exactly one.
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    someone plz remind me wtf question 3 was ?????
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    do you think the grade boundary will be lower or higher than jan 2013? it was 57/70 I think in Jan!
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    (Original post by tumblrgirl)
    do you think the grade boundary will be lower or higher than jan 2013? it was 57/70 I think in Jan!
    About same I reckon.
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    (Original post by Mahinder)
    someone plz remind me wtf question 3 was ?????
    the P(X=r) one I think. First question was mean and sd, 2nd one was the bags stuff, 3rd one envelope one and E(x) and var (x).
 
 
 
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