Mark Scheme
MOCK
GCSE
GCSE Statistics
Paper: 5ST1F_01
GCSE STATISTICS
Paper: 5ST1F_01
Session: Mock
2ST01
2
GCSE STATISTICS
2ST01
NOTES ON MARKING PRINCIPLES
1
Types of mark
M marks: method marks
A marks: accuracy marks
B marks: unconditional accuracy marks (independent of M marks)
2
Abbreviations
cao – correct answer only
isw – ignore subsequent working
oe – or equivalent (and appropriate)
indep – independent
ft – follow through
SC: special case
dep – dependent
awrt – anything which rounds to
3
No working
If no working is shown then correct answers normally score full marks
If no working is shown then incorrect (even though nearly correct) answers score no marks.
4
With working
If there is a wrong answer indicated on the answer line always check the working in the body of the script (and on any
diagrams), and award any marks appropriate from the mark scheme.
If working is crossed out and still legible, then it should be given any appropriate marks, as long as it has not been
replaced by alternative work.
If it is clear from the working that the “correct” answer has been obtained from incorrect working, award 0 marks. Send
the response to review, and discuss each of these situations with your Team Leader.
If there is no answer on the answer line then check the working for an obvious answer.
Any case of suspected misread loses A (and B) marks on that part, but can gain the M marks. Discuss each of these
situations with your Team Leader.
If there is a choice of methods shown, then no marks should be awarded, unless the answer on the answer line makes
clear the method that has been used.
Paper: 5ST1F_01
Session: Mock
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GCSE STATISTICS
2ST01
5
Follow through marks
Follow through marks which involve a single stage calculation can be awarded without working since you can check the
answer yourself, but if ambiguous do not award.
Follow through marks which involve more than one stage of calculation can only be awarded on sight of the relevant
working, even if it appears obvious that there is only one way you could get the answer given.
6
Ignoring subsequent work
It is appropriate to ignore subsequent work when the additional work does not change the answer in a way that is
inappropriate for the question: e.g. incorrect canceling of a fraction that would otherwise be correct
It is not appropriate to ignore subsequent work when the additional work essentially makes the answer incorrect e.g.
algebra.
Transcription errors occur when candidates present a correct answer in working, and write it incorrectly on the answer
line; mark the correct answer.
7
Probability
Probability answers must be given a fractions, percentages or decimals. If a candidate gives a decimal equivalent to a
probability, this should be written to at least 2 decimal places (unless tenths).
Incorrect notation should lose the accuracy marks, but be awarded any implied method marks.
If a probability answer is given on the answer line using both incorrect and correct notation, award the marks.
If a probability fraction is given then cancelled incorrectly, ignore the incorrectly cancelled answer.
8
Linear equations
Full marks can be gained if the solution alone is given on the answer line, or otherwise unambiguously indicated in
working (without contradiction elsewhere). Where the correct solution only is shown substituted, but not identified as
the solution, the accuracy mark is lost but any method marks can be awarded.
9
Parts of questions
Unless allowed by the mark scheme, the marks allocated to one part of the question CANNOT be awarded in another.
Paper: 5ST1F_01
Session: Mock
4
GCSE STATISTICS
5ST1F_01
Question
1
(a)
Working
2ST01
Answer
Mark
1
B1
Saab
1
B1
With the exception of Alfa
2
B1
Jaguar
Notes
(b)
(c)
Less cars were sold in 2009 than 2008
B1
2
a(i)
F at 0.5
a(ii)
J at 0.1
(b)
February has less days than any other
month
2
B1
B1
1
B1
Any other correct contextualised answer is
acceptable.
Paper: 5ST1F_01
Session: Mock
5
GCSE STATISTICS
5ST1F_01
Question
3
(a)
Working
Chocolate
With Flake
10
Without flake 6
Total
16
b(i)
b(ii)
4
(a)
(b)
2ST01
Answer
Vanilla
25
9
34
Total
35
15
50
Notes
B2 for all correct.
16, 34, 50, 35, 15
B1 for any 1 correct.
25/50 or ½ or 0.5 or
50%
16/50 or 8/25 or 0.32
or 32%
2
Eating Out
1
B1
2
M1 for multiplying 1800 by their angle
divided by 360
A1
¼ x £1800
£450
Paper: 5ST1F_01
Session: Mock
Mark
2
B1
B1
6
GCSE STATISTICS
5ST1F_01
Question
5
Paper: 5ST1F_01
Session: Mock
Working
2ST01
Answer
EITHER:
Larger sample.
OR
50 too small a sample
Plus ANY ONE OF:
Telephone directory
does not allow every
person in the town to
have an equal chance
of being chosen.
OR:
The people to receive
the survey should be
chosen randomly from
the town population.
OR:
It could be improved
by a better sampling
method
Mark
2
Notes
B1
B1
Equivalents accepted.
7
GCSE STATISTICS
5ST1F_01
Question
6
(a)
Working
2ST01
Answer
Plot Point at (65, 2.2)
Mark
1
Notes
B1 Tolerance half a square
(b)
Reasonable line but must go through
the mean point
1
B1
(c)
Positive
Plus
The greater the length the greater the
weight (or the converse)
Range 3.4 to 4.0
2
B1
B1
2
M1 (for line on graph)
A1
(e)
Yes
Interpolation or within data range
2
B1
B1
(f)
Range 6.3 to 7.0
1
B1
(g)
Extrapolation or Outside the data set
1
B1
(d)
Line from 90 to lobf
Paper: 5ST1F_01
Session: Mock
8
GCSE STATISTICS
5ST1F_01
Question
7
(a)
Working
2ST01
Answer
Median
Mark
2
Does not include extremes
(b)
20< c ≤ 25
(c)
(d)
Mid points 22.5, 27.5, 32.5, 37.5
25 < c ≤ 30
672.5/23
£29
Notes
B1
B1
1
B1
1
B1 (Accept ‘second class interval’)
2
M1 (correct mid points –may be on
table)
M1 Effort at Σfx/Σf (ft from table)
A1 Any answer which rounds to £29)
8
(a)
0.1 and 0.9 by 2 on second branches
0.6 and 0.4
2
0.1 and 0.9 by 2
(b)
0.4 x 0.9
0.36
B1
B1
2
M1
A1 ft
(c)
100 – (0.9 x 100) or 0.1 x 100
10
2
M1 (for evidence of x by 100)
A1 cao
Paper: 5ST1F_01
Session: Mock
9
GCSE STATISTICS
5ST1F_01
Question
9
(a)
Working
720, 730, 750, 760, 770, 790,
2ST01
Answer
790
Mark
2
800, 820, 830, 850, 870
A1 cao
b(i)
750
b(ii)
830
(c)
Notes
M1 Effort at ordering
Box plot ends 720 and 870, Q1 at 750 Q2
2
B1
B1
3
at 790 and Q3 at 830
M1 A box plot
A1 Ends at correct place cao
A1 All correct (ft for quartiles)
(d)
QWC
Female greater range
4
B1
than male.
Female greater IQR than male.
B1
Female median higher than male.
Female distribution is symmetrical and
B1
Males is symmetrical.
B1 Converses acceptable.
Converses accepted. Correct statistical
language required.
(e)
Paper: 5ST1F_01
Session: Mock
Females weigh a lot more than males.
1
B1
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GCSE STATISTICS
5ST1F_01
Question
10
(a)
Working
2ST01
Answer
ANY TWO OF:
Mark
2
Notes
B1 B1
Easier, Quicker, Cheaper
(b)
All customers of the shopping centre
1
B1
(c)
Do you like or dislike the new
2
B1 Other words possible.
(d)
shopping centre
B1 Boxes or options required.
Like
(Accept Yes or No)
Dislike
Checks questions understandable.
2
Checks that they get the right
B1
B1
information
(e)
ANY 2 POINTS FROM:
2
B1 B1
Not suitable.
Asks two questions in one.
No answer boxes.
Open
Biased / leading
OR
Suggests you agree
Paper: 5ST1F_01
Session: Mock
11
GCSE STATISTICS
5ST1F_01
Question
11
(a)
(b)
Working
2ST01
Answer
417 and 425
Mark
2
Each point plotted correctly
Notes
B1 B1
B1 B1
2
(c)
Increase
2
as the trend line is rising
12
(d)
Quarter 2
(a)
Different age groups
OR:
B1
B1
1
B1 cao
B1
1
Different Genders
Any sensible answer accepted.
Could answer by giving an example e.g
20 to 40 etc. (Must indicate different
Ages)
(b)
The drug is effective
at relieving pain
Paper: 5ST1F_01
Session: Mock
B1
2
B1
OR
(One mark is for ‘effective’ oe the other
The drug is not effective at relieving
is for ‘relieving pain’ oe)
pain
(Equivalents accepted)
12
GCSE STATISTICS
5ST1F_01
Question
(c)
Working
(d)
2ST01
Answer
Qualitative data
Mark
3
A group of people of the same mix as
Notes
B1
B1
the group receiving the drug.
This group receives a placebo oe
B1
(e)
13
(a)
153500/150500 x 100
Pie Chart or bar chart
1
B1 (Accept composite bar chart)
101.99
2
M1 look for attempt at a sensible
fraction x 100
A1 cao
(b)
Gone up; by 7.5%
B1
February was (1.8%) below the
B1
January price
2
B1 (draw a line ‘below’ January)
so the price in
(c)
September is greater than February
B1 (draw a line for greater than
1
February)
(Alternative Answer:
September price £161787 B1 so greater
B1 than February B1)
Paper: 5ST1F_01
Session: Mock
13
GCSE STATISTICS
Paper: 5ST1F_01
Session: Mock
2ST01
14