AQA M1SB 8th of june 2016 unofficial markscheme

This poll is closed

[AQA MS1B 8th of June 2016] What raw mark do you think the A grade will be ?

66 20%

65 5%

64 10%

63 8%

62 13%

61 12%

60 15%

59 5%

5812%

Total votes: 60

xs4

I apologise I do not remember many questions by this is what I have thus far. Contributions towards this and corrections would be welcomed :smile:

- Thank you to everyone that contributed :biggrin:

AQA MS1B Unofficial Mark Scheme

Q1a) PMCC (r) calculation [3 marks]
r = 0.95(9..)
b) Interpret your value for r [2 marks]

Q2a i) Mode = 26 [1 mark]
ii) mean and range or SD [2 marks]
b) find the mean and range or SD [3 marks]
mean = 25.6
range = 45
sd= 5.31-5.26
Q3) probabilities - different ages and bands 1-3
ai) 0.352
ii) 0.136
III)0.158
iv) 0.729
v) 0.267 [9 marks for part a]
b) 0.0308 [5 marks]

Q4) Regression
a) Find the equation of the LSR line
y=181.3+3x (3.0041-3.0044 allowed for b) (181.3-181.5 for a)

b) interpret your value for the gradient in context
c i) (interpolation) estimate the amount dissolved when the temperature
of the water is 68ºC
y=385.3g
ii) Give that the residuals lie between -7 &+9 comment on the accuracy of this estimate
= ....accurate estimate...

Q5)Binomial distribution - loom bands
ai) P(Red loombands = 2)
(50C4) * (0.18)^4 * (0.82)^46 = 0.0262

ii) P( Y≤10) Calculate the probability at most 10 were yellow
Therefore X ~ B(50, 0.15)
P(Y≤10) = 0.8801

iii) P(green and purple<?) bands which gave you
X ~ B(50, 0.5)

iv) P(35<W'&Y'<45)
=>X ~ B(50, 0.8)
(Therefore using the complementary event denoted by H )
H ~ B(50, 0.2)
P(6 ≤ H ≤ 14) = P(H≤14) – P(H≤5) = 0.8913

b) Calculate the mean and variance for 300 red loom bands
μ = np → 300 * 0.18 = 54
σ² = np(1–p) → 54(1–0.18) = 44.3

Q6) Normal distribution
volume of the bottles in a pack of 6
μ= 508.5 , σ = 3.5
ai) P(X>505) = 0.84134

μ=1525 σ=9.6
b) P(X<1540) = 0.94062
ii) P(X>1535?) = 0.14917
iii) P(1515?<X<1540) ?

Q7) confidence intervals people buying euros
a) calculate the limits to 2 dp
b) comment on the claim(s) that [3 marks]
i) ?... rejected claim
ii) 25% of the customers bought fewer than 200 euros
rejected claim - 17.5%

Predicted Boundaries
100 UMS ≈ 72
A ≈ 62
B ≈ 55
C ≈ 48

(edited 7 years ago)

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Reply 1

ODES_PDES

Original post by xs4

I apologise I do not remember many questions by this is what I have thus far. Contributions towards this and corrections would be welcomed :smile:

AQA MS1B Unofficial Mark Scheme

Q1a) PMCC (r) calculation [3 marks]
r = 0.95(9..)
b) Interpret your value for r [2 marks]

2a i) Mode = 26 [1 mark]
ii) mean and range [2 marks]
b) find the mean and range [3 marks]
mean = 25.6
range = 45

3) probabilities - different ages and bands 1-3
ai) 0.136
ii) 0.158
iv) 0.729
v) I can't remember [9 marks for part a]

4) Normal distribution

5)Binomial distribution - loom bands

6) Normal distribution
volume of the bottles in a pack of 6

7) confidence intervals people buying euros
a) calculate the limits to 2 dp
b) comment on the claim(s) that [3 marks]
i)
ii) 25% of the customers bought fewer than 200 euroes
both claims invalid/rejected

danke

Reply 2

Parhomus

Original post by xs4

I apologise I do not remember many questions by this is what I have thus far. Contributions towards this and corrections would be welcomed :smile:

For question 7 wasn't the second claim valid since 20% had spent less than 200 euros and it said at most 25% spent 200 or less.

Reply 3

username1022139

Original post by Parhomus

For question 7 wasn't the second claim valid since 20% had spent less than 200 euros and it said at most 25% spent 200 or less.

I said the first claim was invalid and the second claim was valid.

Reply 4

Kloopz

Original post by Parhomus

For question 7 wasn't the second claim valid since 20% had spent less than 200 euros and it said at most 25% spent 200 or less.

I got this as well

Reply 5

Dapperblook22

Original post by xs4

I apologise I do not remember many questions by this is what I have thus far. Contributions towards this and corrections would be welcomed :smile:

The answer to 3b is 0.0308 [5 marks]

Reply 6

xs4

Original post by Parhomus

For question 7 wasn't the second claim valid since 20% had spent less than 200 euros and it said at most 25% spent 200 or less.

i thought it was the first 10 that bought less than 200
=> 10/40 = 25%

Reply 7

yelash

Original post by xs4

I apologise I do not remember many questions by this is what I have thus far. Contributions towards this and corrections would be welcomed :smile:

AQA MS1B Unofficial Mark Scheme

Q1a) PMCC (r) calculation [3 marks]
r = 0.95(9..)
b) Interpret your value for r [2 marks]

2a i) Mode = 26 [1 mark]
ii) mean and IQR= 26-24=2 [2 marks]
b) i) State two unmeasurable quantities? Mean. standard deviation
ii) find the mean and range [3 marks]
mean = 25.6
range = 45

3) probabilities - different ages and bands 1-3
ai) 0.136
ii) 0.158
iv) 0.729
v) I can't remember [9 marks for part a]

4) Normal distribution

5)Binomial distribution - loom bands

6) Normal distribution
volume of the bottles in a pack of 6

7) confidence intervals people buying euros
a) calculate the limits to 2 dp
b) comment on the claim(s) that [3 marks]
i)
ii) 25% of the customers bought fewer than 200 euroes
both claims invalid/rejected

Put more stuff on from what I remember ^^

Reply 8

Parhomus

Original post by jake4198

I said the first claim was invalid and the second claim was valid.

Same, first one I said that the mean was 381 but I think it might be incorrect since the mean stated lied in the confidence interval so I don't know.

Reply 9

Language student

Does S.D count in question two ii and iii?

Reply 10

Dapperblook22

Original post by xs4

i thought it was the first 10 that bought less than 200
=> 10/40 = 25%

it wasn't the first 10, as otherwise you would be comparing pounds to euros. You had to either convert the euros to pounds, or the pounds to euros and then find that it was 7/40 entries.

Reply 11

Parhomus

Original post by Language student

Does S.D count in question two ii and iii?

Most definitely but range was easier :tongue:

Reply 12

Chickenslayer69

Original post by Parhomus

Same, first one I said that the mean was 381 but I think it might be incorrect since the mean stated lied in the confidence interval so I don't know.

I accepted it and said that it lied in the confidence interval, but the confidence interval was so large it doesn't even make sense...

Did anyone else get a negative lower bound for the confidence interval or was that just me lool

Reply 13

Parhomus

Original post by Chickenslayer69

I know someone who did but I think it was ~257

Reply 14

TIF141

Original post by Dapperblook22

it wasn't the first 10, as otherwise you would be comparing pounds to euros. You had to either convert the euros to pounds, or the pounds to euros and then find that it was 7/40 entries.

Wasn't it 8/40 as one was exactly 166.67 which is 200/1.2? And I think it said 'at most 200', which includes £166.67?

Reply 15

Dapperblook22

Original post by TIF141

Wasn't it 8/40 as one was exactly 166.67 which is 200/1.2? And I think it said 'at most 200', which includes £166.67?

I went for 7 as I think it was more than 200, so not inclusive. I can't remember exactly though, you may be right. We both had a similar method so I am sure we will both get the method marks at least.

Reply 16

nocheloche

Original post by Dapperblook22

it wasn't the first 10, as otherwise you would be comparing pounds to euros. You had to either convert the euros to pounds, or the pounds to euros and then find that it was 7/40 entries.

^ this.

Btw, i think I put that both claims for this question were valid?? Did anyone else get that?

Reply 17

Chickenslayer69

Original post by Parhomus

I know someone who did but I think it was ~257

Crap... forgot to divide by the square root of n, i'm dumb

how many marks was that Q ive literally never done this question wrong

Reply 18

nocheloche

Original post by TIF141

Wasn't it 8/40 as one was exactly 166.67 which is 200/1.2? And I think it said 'at most 200', which includes £166.67?

From what I remember, the question said 'fewer than €200', which is why I disregarded the £166.67 value in the table and so got 7/40.

Reply 19

TIF141

Original post by stardust-dream

^ this.

Btw, i think I put that both claims for this question were valid?? Did anyone else get that?

Yeah, I got that. The first part the confidence interval range was huge so included whatever it was that it wanted, and then the second part was 17.5 or 20% depending on whether you counted 166.67, so yeeah that one'd be valid too