A-LevelMathematicsProbability and statistics9709/62 · Oct/Nov 2018 · Q56 Marks

The Quivers Archery club has 12 Junior members and 20 Senior members. For the Junior members, the mean age is 15.5 years and the standard deviation of the ages is 1.2 years. The ages of the Senior members are summarised by ∑y = 910 and ∑y² = 42 850, where y is the age of a Senior member in years.

Mark scheme

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

[M1] Unsimplified total age divided by their total members (not 12, 20 or 2)
[A1] Correct exact answer (isw rounding), oe (34 years 3 months)
[M1] Σx²/k – 15.5² = 1.2², k = 12 or 20
[A1] Answer wrt 2900
[M1] Their 45750 > 42850 (not 85700 or rounding to 1.8 × 10⁵) in correct variance or std deviation formula (Σx² and addition may not be seen)
[A1] Correct final answer, condone 16.03

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, 6 marks.
Source: A-Level Mathematics, Oct/Nov 2018 Paper 6 Variant 2, question 5.

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