Two groups complete a sustained-attention task. Each participant's score is the number of target symbols correctly identified out of 30.
| Group | Lowest score | Highest score | Mean score |
|---|---|---|---|
| M | 16 | 20 | 18 |
| N | 9 | 27 | 18 |
Explain, using calculations, which group's mean provides the more useful summary of the participants' scores.
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.