A psychologist conducted a study investigating the impact of a five-minute guided meditation on student concentration. Participants completed a concentration task before and after the session, and their performance changes were recorded in Table 2.
| Performance Category | Improved concentration (+) | Worse concentration (-) | No change (0) |
|---|---|---|---|
| Number of students | 24 | 8 | 4 |
Use the data in Table 2 to calculate the value of S S\,S using the sign test. Explain how you calculated this figure.
121 exam-style questions on AQA A Level Psychology Inferential testing (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.