OCR S1 Specimen — Question 6

Exam BoardOCR
ModuleS1 (Statistics 1)
SessionSpecimen
TopicData representation
TypeCompare or interpret cumulative frequency graphs

6
\includegraphics[max width=\textwidth, alt={}, center]{2fb25fc5-0445-44fa-a23e-647d14b1a376-3_803_1180_1018_413} The diagram shows the cumulative frequency graphs for the marks scored by the candidates in an examination. The 2000 candidates each took two papers; the upper curve shows the distribution of marks on paper 1 and the lower curve shows the distribution on paper 2. The maximum mark on each paper was 100.
  1. Use the diagram to estimate the median mark for each of paper 1 and paper 2.
  2. State with a reason which of the two papers you think was the easier one.
  3. To achieve grade A on paper 1 candidates had to score 66 marks out of 100. What mark on paper 2 gives equal proportions of candidates achieving grade A on the two papers? What is this proportion?
  4. The candidates' marks for the two papers could also be illustrated by means of a pair of box-and whisker plots. Give two brief comments comparing the usefulness of cumulative frequency graphs and box-and-whisker plots for representing the data.