Hey there! Sign in to join this conversationNew here? Join for free
    Offline

    3
    ReputationRep:
    (Original post by NSSBB)
    I wrote like this 1. S squared= sigma squared the sample variance is equal to the population variance. 2. The central limit theorem enables us to assume both of the sample means are normal. Because we are not told that the populations are normal but the sample sizes are large enough.

    Actually I think the first and the last one are correct. In terms of the past paper, every time there are this kind of questions
    The CLT point is valid for the question 'What is the relevance of the CLT' in past papers though. Perhaps it might be credited in this paper, but i have my doubts
    Offline

    8
    ReputationRep:
    Posted from TSR Mobile

    I rounded both up. Do you reckon we'll lose a mark for that? I doubt it
    Offline

    0
    ReputationRep:
    (Original post by Jelly150)
    Posted from TSR Mobile

    I rounded both up. Do you reckon we'll lose a mark for that? I doubt it


    I also did this. But I don't think it will make a big difference to the final answer. I think it is fine? ? ?
    Offline

    8
    ReputationRep:
    Posted from TSR Mobile

    It will make no difference to the final answer. It also did say to 2 decimal places. In previous mark schemes it says give a mark for answers between two certain numbers. So it should be fine and get full marks as long as everything else is correct.
    Offline

    0
    ReputationRep:
    (Original post by ninjass)
    My answers - I thought t was fairly standard

    1a) More representative, individual strata estimates availiable
    1b) random process, no interviewer bias

    2) 5.61 and I think you rejected

    3a) When the data isn't bivariate noral
    b) 0.75 and I think you rejected
    You accepted the pmcc question
    e) You HAD TO say about ranks - days where sales of ice cream ranked highly, ranked highly for sunglasses

    4a) 0.7794
    b) 760,302.25
    c) 0.0107

    5a) 1.95 and you rejected
    b) Var of sample = var of population. Samples are independent of each other. CANT MENTION CLT - as its not an assumption, it's a thorem
    c) tricky - 12.7

    6a) Test statistic was 4.1 and you accepted
    b) r= 26.78 s= 16.07
    c) Test statistic was 14.65 you reject

    7a) 19.15%,19.85%
    b) Paul shoud tell them to lover stated weight
    c) n=44

    Who agrees?
    YES for 7c I got 44 but two guys doing it with me got 27! As it said 0.9 as probability I used the 0.05 z value which is 1.6449 (0.05 either side = 0.9 total), whereas they used 1.2816 which is the 0.1 z value. Glad someone else saw it my way, I thought I'd definitely lost the marks
    Offline

    6
    ReputationRep:
    Fair to say:
    A- 65/66
    A*- 70/71

    Given it was slightly harder than fp2 June 2015 I'd guess similarish but also less people do stats 3 than fp2 so might be the same.
    Offline

    18
    ReputationRep:
    did the paragraph in q6 say p=0.3 was estimated? or did they say she believes p=0.3 in the binomial goodness of fit.
    Offline

    1
    ReputationRep:
    does anyone remember the full solution for question 5a to reach the answer 1.95?
    Offline

    17
    ReputationRep:
    Think i got 73/75 cri.

    But it's stats I don't really care. I have no interest in playing Edexcel's stupid games and jump through their stupid hoops any more... just gets in the way of real math

    I'm not bitter

    Posted from TSR Mobile
    Offline

    2
    ReputationRep:
    (Original post by physicsmaths)
    did the paragraph in q6 say p=0.3 was estimated? or did they say she believes p=0.3 in the binomial goodness of fit.
    "believes that the data can be modelled by Binomial distribution with p = 0.3" i think which means the "believes" part refers to the Binomial part of the question and 0.3 wasn't estimated.
    Offline

    18
    ReputationRep:
    (Original post by coolguy123456)
    "believes that the data can be modelled by Binomial distribution with p = 0.3" i think which means the "believes" part refers to the Binomial part of the question and 0.3 wasn't estimated.
    good!, gues i havent lost more stupid marks!
    Offline

    2
    ReputationRep:
    (Original post by physicsmaths)
    good!, gues i havent lost more stupid marks!
    That is what i believe any way, I doubt they'd say that and so far everyone has got the same answer .
    Offline

    1
    ReputationRep:
    Do you reckon putting "population divided into naturally occurring, mutually exclusive groups" would score no points in 1 a? Also, for 3a, would it be ok to say "ranks more important than numerical values"?
    Offline

    3
    ReputationRep:
    (Original post by Rkai01)
    Large populations is for systematic though. I'm annoyed I didn't write for large samples but donno about large population dude
    I think I wrote large populations/samples cos I wasn't sure haha. I really should've went for "representative" though

    Posted from TSR Mobile
    Offline

    3
    ReputationRep:
    I wrote binomial (50,0.3) instead of (4,0.3) Would I loose the hypothesis mark B1? Would i loose any other mark? I stated (50,0.3) in the conclusion aswell will i loose a mark?

    If anyone can write out what they remember from the questions then maybe we can all retry the questions properly & form an unofficial mark scheme!
    Offline

    3
    ReputationRep:
    (Original post by Rkai01)
    Fair to say:
    A- 65/66
    A*- 70/71

    Given it was slightly harder than fp2 June 2015 I'd guess similarish but also less people do stats 3 than fp2 so might be the same.
    i don't see why you compare it to a fp2 paper when this is an s3 paper. comparing to last year's s3 paper which was much harder, i think the gb's will be A*>72, A>66 p.s. last year's fp2 paper was considered to be quite easy i think
    Offline

    0
    ReputationRep:
    (Original post by Euclidean)
    What exactly are you talking about? The estimator for sample mean or sample variance?
    The new estimation of the variance on the addition of the new data.
    Offline

    3
    ReputationRep:
    (Original post by lai812matthew)
    i don't see why you compare it to a fp2 paper when this is an s3 paper. comparing to last year's s3 paper which was much harder, i think the gb's will be A*>72, A>66 p.s. last year's fp2 paper was considered to be quite easy i think
    This is clearly inaccurate: A* boundaries for past few years:
    70
    69
    68
    68
    69 (71)
    66

    It has never been >70 except on an R paper.
    This paper also had several tricks (CLT not at assumption, lose 2 DoF for a chi squared test) and because there were 3 chi squared was on the time pressured side => less time to check => more silly mistakes). Predict A* boundary 68 -69. No way is it 71 let alone higher.
    Offline

    18
    ReputationRep:
    8lol 72 for an A* hahhahahahahaha. banter the paper was abit tricky not trivial. M3 was trivial this year and A* will be atmost 70 i think.
    Offline

    3
    ReputationRep:
    (Original post by Random1357)
    This is clearly inaccurate: A* boundaries for past few years:
    70
    69
    68
    68
    69 (71)
    66

    It has never been >70 except on an R paper.
    This paper also had several tricks (CLT not at assumption, lose 2 DoF for a chi squared test) and because there were 3 chi squared was on the time pressured side => less time to check => more silly mistakes). Predict A* boundary 68 -69. No way is it 71 let alone higher.
    maybe i did not take enough samples of fp2 to consider then, making my standard error large, my fault then...... they do have a very small deviate of marks for each year comparing to other subjects lol.
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    Brussels sprouts
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

    Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

    Quick reply
    Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.