In a survey 55 students were asked to record, to the nearest kilometre, the total number of kilometres they travelled to school in a particular week. The results are shown below. 5 5 9 10 13 13 13 15 15 15 15 16 18 18 18 19 19 20 20 20 20 21 21 21 21 23 25 25 27 27 29 30 33 35 38 39 40 42 45 48 50 50 51 51 52 55 57 57 60 61 64 65 66 69 70

Mark scheme

Marking points from the official mark scheme (May/June 2018). The mark or mark type is shown in brackets.

1. [B1] median correct
2. [B1] LQ and UQ correct
3. [B1] Quartiles and median plotted as box graph with linear scale min 3 values
4. [B1ft] Whiskers drawn to correct end points with linear scale, not thr' box, not joining at top or bottom of box. Ft their UQ and LQ. Whiskers must be with ruler
5. [B1] Label to include 'distance or travelled' and 'km,' allow ‘total km', linear scale, numbered at least 5 – 70.
6. [M1] Attempt to find 1.5 × their IQR and add to UQ or subt from LQ
7. [A1] Correct conclusion from correct working, need both ends. No need to state comparisons.
8. [M1] Compare their 1.5 × IQR (= 48) > gap (20) between UQ and max 70 or LQ and min 5
9. [A1] Correct conclusion from correct working, need both ends. No need to state comparisons