# Edexcel GCSE statistics 2017 unofficial markscheme Watch

Announcements

I don't think anyone has started a thread yet for edexcel stats so thought I would. I guess because it's a pretty unpopular GCSE.

How did everyone find the exam? (higher)

I'm gonna try and remember as many questions as I can and I'll put my answers, but I only think I got about 70% of the paper right so don't go by them as an unofficial markscheme... didn't really revise and I'm not really an A* maths/stats student.

What do you guys think the grade boundaries will be? I think it was easier than last year's so I reckon somewhere between 78 and 82 will be the A* boundary.

A C grade will still be no more than 30% imo.

How did everyone find the exam? (higher)

I'm gonna try and remember as many questions as I can and I'll put my answers, but I only think I got about 70% of the paper right so don't go by them as an unofficial markscheme... didn't really revise and I'm not really an A* maths/stats student.

What do you guys think the grade boundaries will be? I think it was easier than last year's so I reckon somewhere between 78 and 82 will be the A* boundary.

A C grade will still be no more than 30% imo.

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#2

Lmao, the exam was all good up until the last page , I think I did the standardized score the wrong way around :\ (and Icompletely forgot how to do weighted mean)

Grade boundaries won't be that high I think, a C will probably be around 30-40 marks, hopefully I got somewhere between 70-80%

Grade boundaries won't be that high I think, a C will probably be around 30-40 marks, hopefully I got somewhere between 70-80%

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(Original post by

Lmao, the exam was all good up until the last page , I think I did the standardized score the wrong way around :\ (and Icompletely forgot how to do weighted mean)

Grade boundaries won't be that high I think, a C will probably be around 30-40 marks, hopefully I got somewhere between 70-80%

**Gulled Bulhan**)Lmao, the exam was all good up until the last page , I think I did the standardized score the wrong way around :\ (and Icompletely forgot how to do weighted mean)

Grade boundaries won't be that high I think, a C will probably be around 30-40 marks, hopefully I got somewhere between 70-80%

The formula is score - mean divided by standard deviation

I got -0.6 for the standardised score.

The weighted mean (I think) would be (0.35 x 55) + (0.45 x 41) + (0.25 x 57)

I can't remember the actual grades given lol but you multiply the % each component carries by the mark achieved, then add all of those up for the weighted mean.

Yeah, I was reeeaaaallly hoping for an A* until the stupid bloody teacher who marked my work decided he 'didn't want to look like he was over-marking anybody' so gave me 27/40 when I know my grade was worthy of a 32/40 at least. I'm praying that edexcel will remark my coursework when they moderate the few courseworks that were sent off. It can't only be mine that was seriously marked down, but it makes me so pissed because I worked incredibly hard, I did 3 hypotheses and really, really thoroughly investigated them. Used pretty much every statistical method for strand 2 and wrote a good summary. I think I'm probably more likely to get an A grade or a high B. I think I got about 76 in the paper today. If my grade is a B I'll be devastated - I'm expecting an A at least in all of my subjects so I will honestly try to get the coursework thoroughly remarked because that will be where I lost

*so many marks that I really should have been given*. I wish there was a way I could complain.

Good luck for results day!

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#5

(Original post by

What did you get for the standardised score?

The formula is score - mean divided by standard deviation

I got -0.6 for the standardised score.

The weighted mean (I think) would be (0.35 x 55) + (0.45 x 41) + (0.25 x 57)

I can't remember the actual grades given lol but you multiply the % each component carries by the mark achieved, then add all of those up for the weighted mean.

Yeah, I was reeeaaaallly hoping for an A* until the stupid bloody teacher who marked my work decided he 'didn't want to look like he was over-marking anybody' so gave me 27/40 when I know my grade was worthy of a 32/40 at least. I'm praying that edexcel will remark my coursework when they moderate the few courseworks that were sent off. It can't only be mine that was seriously marked down, but it makes me so pissed because I worked incredibly hard, I did 3 hypotheses and really, really thoroughly investigated them. Used pretty much every statistical method for strand 2 and wrote a good summary. I think I'm probably more likely to get an A grade or a high B. I think I got about 76 in the paper today. If my grade is a B I'll be devastated - I'm expecting an A at least in all of my subjects so I will honestly try to get the coursework thoroughly remarked because that will be where I lost

Good luck for results day!

**dreamerkitten**)What did you get for the standardised score?

The formula is score - mean divided by standard deviation

I got -0.6 for the standardised score.

The weighted mean (I think) would be (0.35 x 55) + (0.45 x 41) + (0.25 x 57)

I can't remember the actual grades given lol but you multiply the % each component carries by the mark achieved, then add all of those up for the weighted mean.

Yeah, I was reeeaaaallly hoping for an A* until the stupid bloody teacher who marked my work decided he 'didn't want to look like he was over-marking anybody' so gave me 27/40 when I know my grade was worthy of a 32/40 at least. I'm praying that edexcel will remark my coursework when they moderate the few courseworks that were sent off. It can't only be mine that was seriously marked down, but it makes me so pissed because I worked incredibly hard, I did 3 hypotheses and really, really thoroughly investigated them. Used pretty much every statistical method for strand 2 and wrote a good summary. I think I'm probably more likely to get an A grade or a high B. I think I got about 76 in the paper today. If my grade is a B I'll be devastated - I'm expecting an A at least in all of my subjects so I will honestly try to get the coursework thoroughly remarked because that will be where I lost

*so many marks that I really should have been given*. I wish there was a way I could complain.Good luck for results day!

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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.

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

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.

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

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__
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(Original post by

I think you have done the weighted mean question wrong. You don't utilise the percentages- it didn't ask for it

**SorabVij**)I think you have done the weighted mean question wrong. You don't utilise the percentages- it didn't ask for it

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#8

[QUOTE=dreamerkitten;72361492]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.

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

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

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.

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

Venn diagram question-

Wouldn't the probability for it being over 29 degrees when it's raining be 6/11 as there was 11 days when it was raining and 6 of these had a max temp above 29 degrees

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**Wouldn't the probability for it being over 29 degrees when it's raining be 6/11 as there was 11 days when it was raining and 6 of these had a max temp above 29 degrees

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(Original post by

Venn diagram question-

Wouldn't the probability for it being over 29 degrees when it's raining be 6/11 as there was 11 days when it was raining and 6 of these had a max temp above 29 degrees

**SorabVij**)Venn diagram question-

Wouldn't the probability for it being over 29 degrees when it's raining be 6/11 as there was 11 days when it was raining and 6 of these had a max temp above 29 degrees

My answer is wrong; he IS correct in saying that there is more chance of the higher temp with rain, as the chance of it being over 29 degrees was 0.33 which is lower than 0.54 for rain and over 29 degrees.

I pretty much messed up quite a few questions and only realised it a few hours later... Always the case. I wrote up most of those answers straight after the exam, and have since noticed my mistakes. Oh well :/

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#10

(Original post by

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.

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

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

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.

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

**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**
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#11

On the Venn diagram question how would the answer be 1/25? I think I put like 21/30

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#12

(Original post by

For question 16, a) I got -0.6

**Silverdps**)For question 16, a) I got -0.6

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(Original post by

For question 16, a) I got -0.6

**Silverdps**)For question 16, a) I got -0.6

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(Original post by

On the Venn diagram question how would the answer be 1/25? I think I put like 21/30

**SorabVij**)On the Venn diagram question how would the answer be 1/25? I think I put like 21/30

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#15

Also, for the chain base index question- did u get the actual percentage as 26. Something which is higher than 25%?

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#16

Also, for the chain base index question- did u get the actual percentage as 26. Something which is higher than 25%?

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#17

(Original post by

What did u put for the very last one

**SorabVij**)What did u put for the very last one

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#18

(Original post by

So did I - that was a typo in my answers!!! I missed the - sign.

**dreamerkitten**)So did I - that was a typo in my answers!!! I missed the - sign.

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#19

(Original post by

Also, for the chain base index question- did u get the actual percentage as 26. Something which is higher than 25%?

**SorabVij**)Also, for the chain base index question- did u get the actual percentage as 26. Something which is higher than 25%?

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#20

(Original post by

Yes it was a 26% increase.

**Silverdps**)Yes it was a 26% increase.

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