Participants completed a visual-search task. Their completion times were summarised in the frequency table.
| Completion time (seconds) | Frequency |
|---|---|
| 20 to under 30 | 4 |
| 30 to under 40 | 7 |
| 40 to under 50 | 12 |
| 50 to under 60 | 2 |
Identify the modal class of these completion times. Calculate how many people took part, then calculate what percentage of them are in the modal class. 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.