GCSE · Cumulative frequency & box plots

Cumulative frequency diagramsExam-style questions

How to build a running total from a grouped frequency table, why every point is plotted at the upper class boundary rather than the midpoint, and how to read estimates off the curve in both directions.

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11 questions · GCSE (Higher) level · mark scheme and worked solution on each · no sign-up to try

DifficultyAll Level 2 Level 3 Level 4 Level 5

1
The cumulative frequency diagram shows the battery life, in hours, of 120 mobile phones.(a) Use the diagram to work out the frequency for each of the classes $0 < t \le 2$ , $2 < t \le 4$ , $4 < t \le 6$ , $6 < t \le 8$ and $8 < t \le 10$ .

(b) Work out an estimate for the mean battery life.
Level 5 · 5 marksTry it
2
150 people applied for a job. Each applicant sat a test marked out of 100. The cumulative frequency diagram shows their scores.(a) The 30 applicants with the highest scores will be invited to an interview. Use the diagram to estimate the lowest score an applicant needs in order to be invited to an interview.

(b) A newspaper claims that more than 40% of the applicants scored 45 or less. Use the diagram to decide whether this claim is correct. You must show your working.
Level 5 · 6 marksTry it