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    For question 2, what did you guys set H1 to be? I put that h1 > 0.2...but for the conclusion I just said that the teachers claim was wrong...because the probability of getting more than 4 right was so low....but now that I think about it, h0 should be right. Which was silly because I so much time to spare but I didn't want to spend ages thinking about that question. I did all the working and got (P (X > 4) Something like 0.12. Just the conclusion was messed up. How much marks do you reckon I might loose ? It was 6 marks in total btw..
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      (Original post by lawwainam)
      state the distribution of f(x)!?
      I missed that!
      I just substitute the values of the y-intercept and the x-intercept, is it ok?
      I think that fully specifying the p.d.f gives you 2 marks, one mark for giving the limits of the p.d.f. and another mark for saying it is 0 'otherwise'. Or it could be just one mark.
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      (Original post by lawwainam)
      state the distribution of f(x)!?
      I missed that!
      I just substitute the values of the y-intercept and the x-intercept, is it ok?
      It said to state the distribution of f(x) for all real values, so it's the usual state f(x) thing. ...it was 4 marks...so u might lose 1 mark or 2 I guess
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      (Original post by Spongy)
      For that question, i integrated the f(x) between the limits 0 and 0.5 and showed that the area is equal to one because the area under a p.d.f curve has to equal to one. Then i specified the p.d.f. .
      I suppose there's loads of ways of doing that one. But yours seems to be the most relevant way to tackle it. Now that i think about it :eek:
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        (Original post by snowflakesblues)
        For question 2, what did you guys set H1 to be? I put that h1 > 0.2...but for the conclusion I just said that the teachers claim was wrong...because the probability of getting more than 4 right was so low....but now that I think about it, h0 should be right. Which was silly because I so much time to spare but I didn't want to spend ages thinking about that question. I did all the working and got (P (X > 4) Something like 0.12. Just the conclusion was messed up. How much marks do you reckon I might loose ?
        I have the same working out as yourself, working out P(X=>4) getting and aanswer of 0.12....
        Then i put down accept H0 so the teacher's claim is wrong and that the student was not guessing! IS THIS CORRECT????????????????????? :confused::confused:
        Having seen previous mark schemes -> you get one mark for correctly accepting or rejecting H0 and another mark for giving a statement which is in context.
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        (Original post by cazzy-joe)
        Yeahh that one first I was blank too but then I thought of this.
        X--U[-1,3]
        it said something 40 observations find probability of at least 10 is negative so I found out P(X=negative)=P(X<0)=0-(-1)*1/4=0.25

        Then Y--B(40,0.25) find P(Y>=10)
        If that looks fine

        And how about the multiple choice question where they said to do one-tailed test, did you do alternative hyp more than or less then?? I got confused on that question:mad: I did more then (p>0.2) and X=4 dint fall in critical region so I wrote "Teacher's claim is WRONG".
        I don't remember the hypothesis one but i think i did the same as you for the first one
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        (Original post by Spongy)
        I have the same working out as yourself, working out P(X=>4) getting and aanswer of 0.12....
        Then i put down accept H0 so the teacher's claim is wrong and that the student was not guessing! IS THIS CORRECT????????????????????? :confused::confused:
        Having seen previous mark schemes -> you get one mark for correctly accepting or rejecting H0 and another mark for giving a statement which is in context.
        that's what I said, which was super silly. The teacher can only be wrong is P (X > 4) Is less than 0.05 (5 Sig level). I guess because 0.12 was such a low probability in my mind, I automatically assumed that the teacher was wrong. So Silly! But..the question was also worded really funny.....hopefully the grade boundaries will be low...
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        (Original post by warkan)
        In that lambda question did u reject H0 because there was sufficient evidence??

        and last question yeah i got 4.8 also i think... and the probably of it being less than 5 or smtin ? i got 4 numbers on both denominator and numerator..smtin like 2345/3456

        and for the last one did u find 1-(p(x=0)+p(x=1)) ?
        YEH i got 4 numbers on the denominator and numerator, although i know the top number was 6 thousand and something.. like 6240/5384 (but not that). I really thought it was wrong though because of how much of a not nice number it was! And yeh i think i found 1-(p(x=0)+p(x=1)) for the last one
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        (Original post by snowflakesblues)
        For question 2, what did you guys set H1 to be? I put that h1 > 0.2...but for the conclusion I just said that the teachers claim was wrong...because the probability of getting more than 4 right was so low....but now that I think about it, h0 should be right. Which was silly because I so much time to spare but I didn't want to spend ages thinking about that question. I did all the working and got (P (X > 4) Something like 0.12. Just the conclusion was messed up. How much marks do you reckon I might loose ? It was 6 marks in total btw..
        I think you will lose 2 marks
        the method mark for using the probability
        the answer mark for the contextual statement.
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        (Original post by lawwainam)
        I think you will lose 2 marks
        the method mark for using the probability
        the answer mark for the contextual statement.
        The method mark should be right...I think? Cause I got all the probabilities, just the conclusion bit was wrong. So statement mark is 1 mark? because I wrote not significant, accept h0, the teachers claim of the student guessing is "wrong" <-----this I wrote that as the last sentence of the paragraph....I hope the examiner stops after reading accept h0 ....hehe:P lol jk
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        (Original post by Kooper)
        It usually is, but the null hypothesis has to be a fixed probability, and if the student isn't guessing, it isn't fixed - they could get anything between 1 and 10 out of 10. So we have to use the probability of getting it right by guessing (0.2) as it is the only fixed one available. The 4 out of 10 is only the result of 1 trial, it can't be turned into a probability.

        So
        H0 : p=0.2
        H1 : p>0.2 (they're more likely to get it right if they aren't guessing)

        At least I think that's right.

        ^Sorry if it doesn't make sense, it's a weird question and hard to explain!
        Normally I would've done that, but the wording of the question made me question it a little so I ended up with:

        H0: p>0.2
        H1: p=0.2

        Now obviously the rest of the method is the same, as is the probability at the end so that means I got the opposite conclusion? =[
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        (Original post by warkan)
        markinggg schemee pleaseee??? s1 MS is already out...
        Where can i find the S1 mark scheme?
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          Did everyone put down the assumption statements in context:
          so the binomial one was related to the disease
          and the Poisson one was related to cars arriving at the toll booth.
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          (Original post by snowflakesblues)
          The method mark should be right...I think? Cause I got all the probabilities, just the conclusion bit was wrong. So statement mark is 1 mark?
          According to the 2010 June Mark Scheme. There was 1 method mark for reject/accept.
          But you find out all the probabilities, it should be fine
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          Nooooo I think I lost 1 mark for question 2 as I accepted h0 and then said that meant that the teachers claim was not correct as I thought the teachers claim was H1 :facepalm2: how many marks you guys reckon lost there? 1 mark ?
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          (Original post by snowflakesblues)
          The method mark should be right...I think? Cause I got all the probabilities, just the conclusion bit was wrong. So statement mark is 1 mark? because I wrote not significant, accept h0, the teachers claim of the student guessing is "wrong" <-----this I wrote that as the last sentence of the paragraph....I hope the examiner stops after reading accept h0 ....hehe:P lol jk
          :rolleyes: Then you should only loss 1 mark
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            So was the student guessing or not guessing !!!

            Are we all agreed that we had to accept H0 which is p=0.2
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            (Original post by jit987)
            As far as I remember my answers were: In any random order :p:

            M=15

            Teacher question about guessing accept Ho because it was around 0.12..>0.05 so teacher claim was correct.

            Question about ferry was reject Ho, because it was around 0.04..<0.05 so the ferry had improved in how late it was.

            Positive skewness as Mean>Median>Mode...I calculated Mean to make sure which was 1/6..>Median(0.146...)> Mode(0)

            Got some fraction like 3145/6561 for some answer. Then used that answer for the next part as Binomial (3 , 3145/6561) and did 1 - P(X=0)+P(X=1) using the formula.

            Approximating the Poisson as Normal got P(Z< -2.1), then 1- P(Z< 2.1).

            Finished the paper in 55 minutes but left the 5 marks uniform question out. Got confused with that question and even with 35 minutes to spare couldn't get the right method of (40, 0.25). I did another method of drawing the sketch with interval [-40 ,120]. P(X>=10) equalled the negative part of the graph and by doing this got answer of 3/4.(which sounded reasonable so left it with that) But after coming out of the exam lots of people did (40,0.25)...so lost the marks, any know if I will get 1/2 method marks?

            Can't remember other answers...Someone at least post the QP or MS??????????
            Agreed with most things you say, although I'm confused with the teacher one.. Surely if 0.12>0.05 you don't reject hypothesis because it's insufficient evidence? I thought it was only if it was within the critical region that you reject Everyone seems to be saying what you're saying though so i don't doubt you're right, just would like some explanation
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            For the second to last question the answer came out as a fraction "Like mentioned above", will I get penalized for rounding it to 4 s.f? I then followed up with the next question and used it binomially for the next one.....(last question was 3 marks btw) they don't take marks off for following through right??
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            (Original post by Spongy)
            So was the student guessing or not guessing !!!

            Are we all agreed that we had to accept H0 which is p=0.2
            guessing i think:shifty:
           
           
           
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