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    (Original post by Suits101)
    Hi I'll try an unofficial markscheme:

    1
    (a) 0.70291
    (b) 0.6691
    (c) 0.13271
    (d) 0.1441
    (e) 0.622

    Mean = 31.7 s2 = ?

    3
    (a) P(X > 3) = 0.3503
    (b) P (X < 3) and P (X > 3) = 0.3153
    (c) Show E(X) = 3.08, Var(x) = 2.77363
    (d) Poisson distribution cannot have an upper limit, people don't borrow books at a constant average rate
    (e)(i) Mean = 30.8p
    (e)(ii) Standard deviation = 16.7p

    4
    (a) k = 10
    (b) P = 0.70
    (c) E(X) = 0.05
    (d) Integrate, ans = 1/300
    (e) SD(X) = 0.02895

    5
    (a) Test statistic = 2.3386, CV = 2.706 so accept null
    (b) comment

    6
    (a) Test statistic = -2.20794, reject null
    (b)(i) 16.7 +- 1.80
    (b)(ii) Claim not valid because 18.2 lies in CI
    (c) -

    7
    (a) Draw graph - DENSITY function, so have to differentiate
    (b) 73/24
    Pretty much all of your answers are the same as mine, I'll put up a mark scheme on the first page
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    (Original post by Suits101)
    Hi I'll try an unofficial markscheme:

    1
    (a) 0.70291
    (b) 0.6691
    (c) 0.13271
    (d) 0.1441
    (e) 0.622

    Mean = 31.7 s2 = ?

    3
    (a) P(X > 3) = 0.3503
    (b) P (X < 3) and P (X > 3) = 0.3153
    (c) Show E(X) = 3.08, Var(x) = 2.77363
    (d) Poisson distribution cannot have an upper limit, people don't borrow books at a constant average rate
    (e)(i) Mean = 30.8p
    (e)(ii) Standard deviation = 16.7p

    4
    (a) k = 10
    (b) P = 0.70
    (c) E(X) = 0.05
    (d) Integrate, ans = 1/300
    (e) SD(X) = 0.02895

    5
    (a) Test statistic = 2.3386, CV = 2.706 so accept null
    (b) comment

    6
    (a) Test statistic = -2.20794, reject null
    (b)(i) 16.7 +- 1.80
    (b)(ii) Claim not valid because 18.2 lies in CI
    (c) -

    7
    (a) Draw graph - DENSITY function, so have to differentiate
    (b) 73/24
    s^2 = 2.96
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    (Original post by MahuduElec)
    Nice format, However you sill left it as claim may be vaild
    Check edit again! Lol! We're too slow/fast for each other
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    (Original post by Suits101)
    Check edit! Lol! We're too slow/fast for each other
    lmao ifkr
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    (Original post by sam_97)
    Pretty much all of your answers are the same as mine, I'll put up a mark scheme on the first page
    Great job, thanks

    Now to tally up the damage...
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    Do you think I'll get any marks for this?

    I said x bar was 31.7

    Then said miu was 31.7 +- whatever I worked the other part out to be (with an incorrect s^2) - I forgot about this question and rushed it at the end and hence made a mess of it
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    (Original post by Suits101)
    Great job, thanks

    Now to tally up the damage...
    No problem, it's on the first page now!

    Have you got any other maths exams left?
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    (Original post by Suits101)
    Do you think I'll get any marks for this?

    I said x bar was 31.7

    Then said miu was 31.7 +- whatever I worked the other part out to be (with an incorrect s^2) - I forgot about this question and rushed it at the end and hence made a mess of it
    Definitely. It was only 4 marks anyway, so I wouldn't worry about it too much!
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    (Original post by sam_97)
    No problem, it's on the first page now!

    Have you got any other maths exams left?
    Finished with maths now 😄 Glad I didn't carry on with further or I'd finish way later!

    How about you?
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    (Original post by Suits101)
    Finished with maths now 😄 Glad I didn't carry on with further or I'd finish way later!

    How about you?
    Nice one! Which other subjects are you doing?

    I've still got FP2, D1 and M2 left
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    (Original post by Suits101)
    Hi I'll try an unofficial markscheme:

    1
    (a) 0.70291
    (b) 0.6691
    (c) 0.13271
    (d) 0.1441
    (e) 0.622

    2. Mean = 31.7 s2 = 2.96

    3
    (a) P(X > 3) = 0.3503
    (b) P (X < 3) and P (X > 3) = 0.3153
    (c) Show E(X) = 3.08, Var(x) = 2.77363
    (d) Poisson distribution cannot have an upper limit, people don't borrow books at a constant average rate
    (e)(i) Mean = 30.8p
    (e)(ii) Standard deviation = 16.7p

    4
    (a) k = 10
    (b) P = 0.70
    (c) E(X) = 0.05
    (d) Integrate, ans = 1/300
    (e) SD(X) = 0.02895

    5
    (a) Test statistic = 2.3386, CV = 2.706 so accept null
    (b) comment

    6
    (a) Test statistic = -2.20794, reject null
    (b)(i) 16.7 +- 1.80
    (b)(ii) Claim not valid because 18.2 lies in CI
    (c) -

    7
    (a) Draw graph - DENSITY function, so have to differentiate
    (b) 73/24
    Got pretty much the same👌
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    How did you do the one where it had the probabillity of one being less than three and the other being more than three?, 3b i think, would it not be , ( the probabillity of the first being less x the probabillity times the second being more X2! ) as they where the same probabillitys
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    how many marks would I lose for using normal instead of students t in 6b
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    (Original post by Sam1231)
    How did you do the one where it had the probabillity of one being less than three and the other being more than three?, 3b i think, would it not be , ( the probabillity of the first being less x the probabillity times the second being more X2! ) as they where the same probabillitys
    It looks like he did 2(0.35x0.45) to get that answer, guess I got it wrong. Brain fart and only put (0.35x0.45) = 0.1575
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    (Original post by Ayeros)
    It looks like he did 2(0.35x0.45) to get that answer, guess I got it wrong. Brain fart and only put (0.35x0.45) = 0.1575
    Ohh i did 0.35(1-0.35) x2 😭
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    (Original post by Sam1231)
    Ohh i did 0.35(1-0.35) x2 😭
    I'm not sure if we even get working out marks for these questions, I'm doubtful... I hope I haven't made other stupid mistakes too!
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    Would you get any marks for drawing F(x) even if you found f(x) in part b?
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    (Original post by Sam1231)
    31.7 for the mean and 2.96 for the variance ( it asked for variance not sd by the way )
    Ah, Yeah I got that. Also went for the midpoint for the mean, But I thought that was the sample mean while it wanted the population mean so I was confused, Think it's right though.

    As always I couldn't think of reasons why It's not a poisson distribution, I pretty much take off two marks on every paper knowing I'll get that one wrong. What was the answer?
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    was it just 0.35x0.45 for that one question?
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    (Original post by irMike)
    Ah, Yeah I got that. Also went for the midpoint for the mean, But I thought that was the sample mean while it wanted the population mean so I was confused, Think it's right though.

    As always I couldn't think of reasons why It's not a poisson distribution, I pretty much take off two marks on every paper knowing I'll get that one wrong. What was the answer?
    I think its because it must be open ended , and there is likelly to be peak times
 
 
 
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