Find the number of buses that travelled a distance between 15000 and 20000 kilometres.

Use the cumulative frequency curve to find the median distance.

Use the cumulative frequency curve to find the lower quartile.

Use the cumulative frequency curve to find the upper quartile.

Hence write down the interquartile range.

Write down the percentage of buses that travelled a distance greater than the upper quartile.

Find the number of buses that travelled a distance less than or equal to 12 000 km.

Find the value of m.

The smallest distance travelled by one of the buses was 2500 km.
The longest distance travelled by one of the buses was 23 000 km.

On graph paper, draw a box-and-whisker diagram for these data. Use a scale of 2 cm to represent 5000 km.

28 − 20     (A1)

Note: Award (A1) for 28 and 20 seen.

8     (A1)(G2)

[2 marks]

13500     (G2)

Note: Accept an answer in the range 13500 to 13750.

[2 marks]

10000     (G1)

Note: Accept an answer in the range 10000 to 10250.

[1 mark]

16000     (G1)

Note: Accept an answer in the range 16000 to 16250.

[1 mark]

6000     (A1)(ft)

Note: Follow through from their part (b)(ii) and (iii).

[1 mark]

25%     (A1)

[1 mark]

11     (G1)

[1 mark]

30 − 8  OR  22     (M1)

Note: Award (M1) for subtracting 30 − 8 or 22 seen.

15750     (A1)(G2)

Note: Accept 15750 ± 250.

[2 marks]

(A1)(A1)(A1)(A1)

Note: Award (A1) for correct label and scale; accept “distance” or “km” for label.

(A1)(ft) for correct median,
(A1)(ft) for correct quartiles and box,
(A1) for endpoints at 2500 and 23 000 joined to box by straight lines.
Accept ±250 for the median, quartiles and endpoints.
Follow through from their part (b).
The final (A1) is not awarded if the line goes through the box.

[4 marks]