Elena wanted to investigate the stress levels of night-shift and day-shift healthcare workers after participating in a 4-week mindfulness intervention.
She sampled two groups of workers who had completed the mindfulness programme:
Elena asked the workers to rate their post-intervention stress levels. She used a scale ranging from 1 to 10, where 1–5 was classified as ‘low stress’ and 6–10 was classified as ‘high stress’.
| Shift Type | Workers with ‘low stress’ post-intervention | Workers with ‘high stress’ post-intervention |
|---|---|---|
| Night-shift | 8 | 17 |
| Day-shift | 15 | 10 |
Complete Table 2 to calculate the chi-squared statistic (χ2\chi^2χ2) for Elena's data to two decimal places.
| Observed (O) | Expected (E) | O–E | (O–E)2(O–E)^2(O–E)2 | (O–E)2/E(O–E)^2 / E(O–E)2/E | ||
|---|---|---|---|---|---|---|
| Night-shift | ‘Low stress’ | 8 | 11.5 | |||
| ‘High stress’ | 17 | 13.5 | ||||
| Day-shift | ‘Low stress’ | 15 | 11.5 | |||
| ‘High stress’ | 10 | 13.5 | ||||
| Chi-squared (χ2\chi^2χ2) = |
Practise Edexcel A Level Psychology Research methods and skills with exam-style questions for A Level Psychology. 657 questions covering Research methods and skills, matched to the Edexcel A Level Psychology (9PS0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.
