Edexcel GCSE statistics 2017 unofficial markscheme Watch

Nano242
Badges: 0
Rep:
?
#41
Report 1 year ago
#41
I do believe that the answer for standardised score was -0.7 not -0.6 because I confirmed it with my teacher afterwards (memorised the question). About the question were you had to read of the trend line wasn't it 38? Not 28?
0
reply
Nano242
Badges: 0
Rep:
?
#42
Report 1 year ago
#42
(Original post by Silverdps)
For question 16, a) I got -0.6
The answer is -0.7 not -0.6. Literally cross checked with everyone including my teacher
0
reply
Nano242
Badges: 0
Rep:
?
#43
Report 1 year ago
#43
(Original post by dreamerkitten)
HERE ARE MY ANSWERS (the ones I can remember) TO THE GCSE STATS 2017 HIGHER PAPER.
I probably wouldn't recommend using as an unofficial markscheme. I forgot a couple questions, and forgot the order. I only remembered 14 of them. and I don't think I got many answers right but here goes. Let me know what you guys got if you can remember !! Correct me where I'm wrong.





QUESTION 1 – TIME SERIES GRAPH.


This was 4 marks to pretty much just draw a trend line and read off what the graph stated, I can’t remember it.


MARKS = 4


QUESTION 2 – ELECTRONIC TABLET USERS

  • a) 8 } For these 2 it was just reading off the graph [1]
  • b) 28 } and doing 87 – 59 = 28 (or something like that) [2]
  • c) No, as there may be a different number of people in the UK and USA and we only know the % rather than actual numbers. Trends may also differ significantly for each country. [1]
  • d) IQR and Median were higher for tablet users, suggesting that overall the average age of a smartphone user is younger than for a tablet user (in the USA). Plus reference to the values and the difference. [4]



MARKS = 8


COMPOSITE BAR CHART QUESTION

A, b, and c were 6 easy marks – you just had to read off the chart and then draw a new one.

  • - 35-56 year olds - 10% more guessed the price of a stamp correct, but both those and the 16-34 guessed too low(?) similarly. Plus evidence in the form of values/percentage. [2]



MARKS = 8


TELEPHONE INTERVIEW QUESTION

  • a) Electoral roll/register [1]
  • b) Is cheaper as no postage costs for researcher or respondent, so higher response rate. [1]
  • c) One source of bias – interviewers may choose people they know to interview [1]
  • d) 80% said they would vote [2]
  • e) Method 1 = cluster sampling and Method 2 = stratified sampling [2]
  • f) Method two is better because 1) you will not get too many of a certain type of person (i.e. males) 2) less chance of bias [2]



MARKS = 9


BOX PLOT QUESTION

  • a) The box plot can be used to support this as it is slightly negatively skewed, and the median value shows that over 50% paid over 200k for their house [1]
  • b) 1.5 x IQR + UQ = 455,000. 500,000 is higher than the upper outlier boundary so is an outlier [3]



MARKS = 4


FORMS OF DATA

  • a) Age, as it is quantitative (which one can be shown in a stem&leaf) [2]
  • b) Time taken, as it will be discrete and has suitable class widths(?) [2]
  • c) Median (The name of the statistic needed) [1]



MARKS = 5


BAKER COLLECTING DATA QUESTION

  • a) Why he would have to collect primary data: he is the first to carry out this study [1]
  • b) If the sample is too small it will not be representative [1]
  • c) Tick boxes with non-overlapping values (I did less than 0.5 miles, 0.5-1 mile, 1.1-1.5 miles, 1.6-2 miles, more than 2 miles) [2]



MARKS = 8


SPEARMAN’S RANK CORRELATION COEFFICIENT

  • a) Show the sum of d^2 is 10: 0+0+1+4+4+1+0 = 10 [1]
  • b) SRCC = 0.82 [3]
  • c) Relatively strong correlation [1]
  • d) Yes, because the positive correlation suggests that the higher ice cream consumption has a relationship with the GDP value thing. [2]



MARKS = 7


CHAIN BASE INDEX

  • a) At first the prices increased rapidly, then they slowly fell by 5% by 2015. [1]
  • b) 2011 price = £3304.88 (3032 + 9% increase). [1]
  • c) Find the price for 2015. Show that if it increased by 25% it would be (something like) £3720 and the price for 2015 is £3820 so more than a 25% increase. [2]



MARKS = 4


VENN DIAGRAM QUESTION

  • a) 19/30 [1]
  • b) 16/30 [2]
  • c) 1/25 chance [2]
  • d) No, Greg is wrong. Chance of over 29 degrees was 10/30, chance of over 29 when rain was 6/30. So more likely to be over 29 when NOT raining. [3]


These are just guesses at what I put, I can’t remember what I actually answered for a and b... I can't remember the questions!!! Venn Diagram was: 10/30 over 29 degrees, 6/30 rain and over 29, 5/30 rain and 9/30 neither.


MARKS = 8


GEESE CAPTURE RECAPTURE QUESTION

I didn’t revise this topic and probably got it all wrong.

  • a) I got 500 but I think the answer was actually 402. [2]
  • b) It allowed the geese to move around as they would naturally, to distribute themselves. [1]
  • c) No, because the population may have increased more than he thought, he only took one sample. More offspring may have been born, geese could have died or moved to live somewhere else. [2]



MARKS = 5


WEIGHTED MEAN AND STANDARD DEVIATION

  • a) Mean = 51 (based on the scores I think it gave). I can’t remember his scores, I think it was 55, 41 and 57? But you had to find the mean. [1]
  • b) Weighted mean will be less because each component counts for a different % so one holding more weight counts for the most amount of mark, for example. [1]
  • c) Weighted mean = (0.35 x 55) + (0.45 x 41) + (0.25 x 57). I don’t know the exact marks or weightings, sorry, but I THINK that is the formula. [2]
  • d) Number of students higher than him – I got something like 28. I just used the graph to add up the frequencies and then halved the class width that he was in and added that lol. [2]
  • e) 11.5 (or something like that was what I got for the Standard deviation.) [2]
  • f) SD is better because it will show how the data is spread and how close to the mean average it is. [1]



MARKS = 9


QUESTION 15. BINOMIAL DISTRIBUTION, RED/BLUE MARBLES

  • a) 0.7 chance of red [1]
  • b) 0.49 chance of red both times [2]
  • c) 0.83. I can’t remember exactly what it askes, but it was something like more than ½ of 5? This wording was confusing but I did p^5, 5p^4q, 10p^3q^2. Which would be 0.16 + 0.36 + 0.31 = 0.83 [3]
  • d) Show that the most likely number is 4 = 5p^4q worked out is 0.36 to 1dp = 0.4 which is 4 marbles [3]
  • e) No, binomial can only be used for independent trials. [2]



MARKS = 11


QUESTION 16. STANDARDISED SCORES AND NORMAL DISTRIBUTION.

  • a) 0.6 (plus working out) [2]
  • b) She did better in the vault, as her standardised score was higher for that than the beam. Evidence in the fact that -0.6 < 0.5 [2]
  • c) Could it be modelled by a normal distribution? NO, as 95% should lie between 13.3 and 15.7 and the highest score at 15.3 is below that 95%. Plus working to show mean +- 2 sd. [4]



MARKS = 8


I'm sorry to say but you got your standardised score question wrong. It was meant to be -0.7. For the binomial one it was meant to be because they used conditional probability not independent, because they said they would remove the marble and not replace it.the answer for the capture and recapture was 402. And I do believe that it was meant to be 38 instead of 28 for the second question you mentioned.
0
reply
dreamerkitten
Badges: 8
Rep:
?
#44
Report Thread starter 1 year ago
#44
(Original post by Nano242)
I'm sorry to say but you got your standardised score question wrong. It was meant to be -0.7. For the binomial one it was meant to be because they used conditional probability not independent, because they said they would remove the marble and not replace it.the answer for the capture and recapture was 402. And I do believe that it was meant to be 38 instead of 28 for the second question you mentioned.
Are you sure about the binomial question? for the first part it definitely said that they removed the marble and then put it back.
And then for the final part they said 'would you still be able to use binomial if they didn't replace the marble?' and for that question the answer would have been no, because binomial can only be used for independent trials and not conditional probability.

Capture recapture was definitely 402, I didn't revise the formula for the exam but checked afterwards.

And I can't remember what I actually answered for question 2 - what I posted on here was just a guess based on the figures I can remember. I know I answered something ending in 8 but couldn't remember the full number.
0
reply
arnav_202
Badges: 6
Rep:
?
#45
Report 1 year ago
#45
(Original post by Nano242)
The answer is -0.7 not -0.6. Literally cross checked with everyone including my teacher
exactly, i've been arguing over my friends over this.
0
reply
SorabVij
Badges: 10
Rep:
?
#46
Report 1 year ago
#46
I got -2/3 for that standardised score question. Is that wrong?
0
reply
dreamerkitten
Badges: 8
Rep:
?
#47
Report Thread starter 1 year ago
#47
(Original post by arnav2002)
exactly, i've been arguing over my friends over this.
I think people got -0.6 because the answer was -0.6666666 and they didn't round it to -0.7 :/
My calculator actually gave me a straight answer of -0.6, no decimals. I know the mean score was 14.5 and the sd was 0.6 but I can't remember the actual score we were given so that I can rework it out to find where I went wrong...
0
reply
arnav_202
Badges: 6
Rep:
?
#48
Report 1 year ago
#48
(Original post by SorabVij)
I got -2/3 for that standardised score question. Is that wrong?
thats correct
0
reply
SorabVij
Badges: 10
Rep:
?
#49
Report 1 year ago
#49
(Original post by dreamerkitten)
I think people got -0.6 because the answer was -0.6666666 and they didn't round it to -0.7 :/
My calculator actually gave me a straight answer of -0.6, no decimals. I know the mean score was 14.5 and the sd was 0.6 but I can't remember the actual score we were given so that I can rework it out to find where I went wrong...
Was the answer -0.6666
0
reply
JAP63
Badges: 5
Rep:
?
#50
Report 1 year ago
#50
[QUOTE=SorabVij;72387664]
(Original post by JAP63)
Did the question state 2 days selected? I thought it just said find the probability of it being a higher temp of 29, raining or both
Two of the days are selected at random.
Find the probability that on both of these days the max temp was above 29 and it rained!
Hence the first of the 2 days is 6/30
the 2nd is 5/29
0
reply
Rp3213
Badges: 10
Rep:
?
#51
Report 1 year ago
#51
ye i got a decimal
0
reply
Rp3213
Badges: 10
Rep:
?
#52
Report 1 year ago
#52
For the last question, i wrote it may be modelled by a normal distribution as the highest value is within 3 standard deviations away from the mean. However we do not know the minimum value so we are unable to tell is it is also 3 standard deviation away from the mean.
0
reply
Rp3213
Badges: 10
Rep:
?
#53
Report 1 year ago
#53
(Original post by dreamerkitten)
I think people got -0.6 because the answer was -0.6666666 and they didn't round it to -0.7 :/
My calculator actually gave me a straight answer of -0.6, no decimals. I know the mean score was 14.5 and the sd was 0.6 but I can't remember the actual score we were given so that I can rework it out to find where I went wrong...
i got -0.6 as well
0
reply
Rp3213
Badges: 10
Rep:
?
#54
Report 1 year ago
#54
For the question about surveying by using a telephone. I wrote it would be quicker as respondents could respond immediately. Would I get the mark?
0
reply
dreamerkitten
Badges: 8
Rep:
?
#55
Report Thread starter 1 year ago
#55
(Original post by Rp3213)
For the question about surveying by using a telephone. I wrote it would be quicker as respondents could respond immediately. Would I get the mark?
Yes, definitely. I think that would be the obvious one to get a mark - I just decided to answer something different.
0
reply
rainbows4life
Badges: 1
Rep:
?
#56
Report 1 month ago
#56
HELP!!!!!!!! Does anyone know where the official mark scheme is LET ME KNOW!!!
0
reply
rainbows4life
Badges: 1
Rep:
?
#57
Report 1 month ago
#57
helppppppp
0
reply
gullyyt
Badges: 12
Rep:
?
#58
Report 1 month ago
#58
(Original post by rainbows4life)
HELP!!!!!!!! Does anyone know where the official mark scheme is LET ME KNOW!!!
check the edexcel website???
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Latest
My Feed

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.

Personalise

University open days

  • Manchester Metropolitan University
    Undergraduate Open Day Undergraduate
    Wed, 19 Jun '19
  • University of West London
    Undergraduate Open Day - West London Campus Undergraduate
    Wed, 19 Jun '19
  • University of Warwick
    Undergraduate Open Day Undergraduate
    Fri, 21 Jun '19

How did your AQA A-level Biology Paper 3 go?

Loved the paper - Feeling positive (283)
15.21%
The paper was reasonable (1035)
55.62%
Not feeling great about that exam... (403)
21.66%
It was TERRIBLE (140)
7.52%

Watched Threads

View All
Latest
My Feed