Nadia investigated whether a virtual reality (VR) safety training program was more effective than a traditional slide-based training program. She recorded whether participants in each group passed or failed a subsequent hazard-perception test on their first attempt. Her results are shown in Table 1.
| VR-based training | Slide-based training | |
|---|---|---|
| Passed first attempt | 45 | 22 |
| Failed first attempt | 15 | 38 |
State two reasons why Nadia used a chi-squared test to analyze her data.
Practise Edexcel A Level Psychology Methods with exam-style questions for A Level Psychology. 100 questions, 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.