A psychologist records how long 30 participants take to complete a concentration task.
| Completion time (minutes) | Frequency |
|---|---|
| 1 to under 2 | 3 |
| 2 to under 3 | 9 |
| 3 to under 4 | 12 |
| 4 to under 5 | 6 |
Identify the completion-time interval that contains the greatest number of participants.
Calculate the percentage of participants who finished in less than 3 minutes. Show your working.
173 exam-style questions on OCR GCSE Psychology 7.3 Analysing Research, covering 7.3.1 Types of Data, 7.3.2 Measures of central tendency, 7.3.3 Other descriptive statistics, 7.3.4 Tables, Charts and Graphs, 7.3.5 Reliability, 7.3.6 Validity and effects on validity, and 7.3.7 Sources of bias. Each one has a worked solution and a mark scheme showing where the marks go.