A-LevelMathematicsProbability and statistics9709/53 · May/June 2022 · Q23 Marks

Twenty children were asked to estimate the height of a particular tree. Their estimates, in metres, were as follows. 4.1, 4.2, 4.4, 4.5, 4.6, 4.8, 5.0, 5.2, 5.3, 5.4, 5.5, 5.8, 6.0, 6.2, 6.3, 6.4, 6.6, 6.8, 6.9, 19.4

(a)Find the mean of the estimated heights.[1]
(b)Find the median of the estimated heights.[1]
(c)Give a reason why the median is likely to be more suitable than the mean as a measure of the central tendency for this information.[1]

Mark scheme

Marking points from the official mark scheme (May/June 2022). The mark or mark type is shown in brackets.

[B1] [123.4 / 20] = 6.17. Accept 6 m 17 cm, 1234 / 200
[B1] 10th + 11th / 2 = 5.4 + 5.5 / 2 = 5.45 (m). Accept 5 m 45 cm.
[B1] The mean is unduly influenced by an extreme value, 19.4. Comment must be within context.

On Oracle Prep you can write or photograph your own answer and have it marked by AI against this mark scheme, with feedback on what you missed.

Topic: Probability and statistics, A-Level Mathematics (syllabus 9709). Structured question, 3 marks.
Source: A-Level Mathematics, May/June 2022 Paper 5 Variant 3, question 2.

Questions and mark schemes are from past examination papers and remain the copyright of the exam board. How Oracle Prep builds its content