June 2023 Paper 2 Q13

OCR ACurrent spec10 marksData Processing Large Data Set

13 The scatter diagram uses information about all the Local Authorities (LAs) in the UK, taken from the 2011 census.

For each LA it shows the percentage (\(x\)) of employees who used public transport to travel to work and the percentage (\(y\)) who used motorised private transport.

“Public transport” includes train, bus, minibus, coach, underground, metro and light rail.
“Motorised private transport” includes car, van, motorcycle, scooter, moped, taxi and passenger in a car or van.

Scatter diagram of percentage using motorised private transport (y, 0 to 90) against percentage using public transport (x, 0 to 80): a dense cluster at x about 2 to 15, y about 55 to 80, with points trailing down to x about 50 to 63, y about 11 to 23; outlier A at about (1, 23) and outlier B at about (29, 4)

(a) Most of the points in the diagram lie on or near the line with equation \(x + y = k\), where \(k\) is a constant.

(i) Give a possible value for \(k\). [1]

(ii) Hence give an approximate value for the percentage of employees who either worked from home or walked or cycled to work. [1]

(b) The average amount of fuel used per person per day for travelling to work in any LA is denoted by F.
Consider the two groups of LAs where the percentages using motorised private transport are highest and lowest.

(i) Using only the information in the diagram, suggest, with a reason, which of these two groups will have greater values of F than the other group. [1]

A student says that it is not possible to give a reliable answer to part (b)(i) without some further information.

(ii) Suggest two kinds of further information which would enable a more reliable answer to be given. [2]

(c) Points \(A\) and \(B\) in the diagram are the most extreme outliers. Use their positions on the diagram to answer the following questions about the two LAs represented by these two points.

(i) The two LAs share a certain characteristic.
Describe, with a justification, this characteristic. [2]

(ii) The environments in these two LAs are very different.
Describe, with a justification, this difference. [2]

(d) A student says that it is difficult to extract detailed information from the scatter diagram.
Explain whether you agree with this criticism. [1]

Scheme	Marks	AO
(i) \(k = 70\) to 80 inclusive	B1	1.2
	[1]
(ii) \(100 -\) their \(k\)	B1FT	2.2a
	[1]

Mark scheme (b)

Scheme	Marks	AO
(i) The group with highest usage of private (motorised) transport (top left), because private transport uses more fuel than public transport (for the same travel distance, per person).	B1	2.2b
	[1]
(ii) e.g. Lengths of journeys (or distance travelled) and	B1	2.4
e.g. how many people travel in each vehicle used (or ‘occupancy’ of each mode)	B1	2.4
	[2]

Notes

(b)(i)

B1: For a clear explanation that must both identify the group unambiguously (e.g. ‘top left’, ‘least public transport use’) and give a reason.
Accept equivalent justifications e.g. ‘each individual uses more fuel’

(b)(ii)

B1 B1: For two sensible distinct suggestions. Acceptable answers include:

The type or amount of fuel used (by different modes of transport)
Proportion or usage of Electric Vehicles
Types of vehicle used (or available)
Proportion of the different modes of transport within each category
The occupancy of each mode (or e.g. car sharing)
Proportion of full-time vs part-time working patterns

Do not accept:

Population size (because \(F\) is per person)
Number of those not in work (because \(F\) is for employees)
References to emissions e.g. ‘given off’ (because \(F\) is the amount of fuel used)

Mark scheme (c)

Scheme	Marks	AO
(i) Large percentage walk/cycle/work from home	B1	2.2b
Small area	B1	2.4
	[2]
(ii) \(A\) is rural, \(B\) is urban	B1	2.2b
Public transport is absent in \(A\) but used in \(B\) or, eg, Those in \(B\) who don’t walk, don’t use cars, so there is probably a lot of traffic, so \(B\) is urban. No public transport in \(A\) so \(A\) is rural	B1	2.4
	[2]

Notes

(c)(i)

B1: For the shared characteristic (any of walk/cycle/work from home). Condone ‘these have the lowest total proportion using public or motorised private transport combined’ but do not accept only ‘lower percentage using motorised private transport’ or ‘lower percentage using public transport’ – need both

B1: For a justification (must be related to the LA). Acceptable answers include:

‘less need to travel to work’
‘shorter journeys’
‘better walking/cycling infrastructure’

But not just ‘more work from home’ (this is the characteristic)

(\(A\) is Scilly Isles, \(B\) is City of London)

(c)(ii)

B1: B1 for identifying the difference in environment (must make a comparison e.g. ‘\(A\) is more rural than \(B\)’). Accept clearly equivalent statements e.g. ‘city’ or ‘countryside’

B1: B1 for justification.
Cannot just restate the data so do not accept e.g. ‘\(A\) has low public transport use’ – must give a justification as to why this might be.
Accept e.g. ‘less availability of public transport’
Other sensible answers may be seen e.g. ‘motorised private transport is almost absent in \(B\) but more widely used in \(A\)’

Mark scheme (d)

Scheme	Marks	AO
Some points are too close together to read	B1	2.3
	[1]

Notes

B1: Must make a specific criticism of the graph related to reading values. Acceptable answers include:

‘the scale is not precise enough to read detailed values’
‘closely clustered points mean it is hard to read’
‘there are no gridlines so cannot read exact values’

Do not accept generic statements such as ‘the data may not be accurate’ or references to information not included on the graph.