A transport planner is researching sustainable commuting habits across different age groups in a major metropolitan area. They surveyed 450 daily commuters, categorising them by age bracket and their primary mode of micro-mobility or transport used for their morning commute. The frequency data collected is displayed in the contingency table below.
| Electric Scooter | Electric Bicycle | Traditional Bicycle | Public Transit | Personal Vehicle | Walk / Run | |
|---|---|---|---|---|---|---|
| Young Adults (18–30) | 42 | 38 | 15 | 35 | 12 | 28 |
| Mid-career (31–50) | 25 | 45 | 22 | 40 | 30 | 18 |
| Senior Professionals (51 and over) | 10 | 20 | 18 | 32 | 15 | 5 |
Determine the degrees of freedom required to test for a significant association between age group and primary commute mode using a Chi-square test.
513 exam-style questions on OCR A Level Psychology Data recording, analysis and presentation. Each one has a worked solution and a mark scheme showing where the marks go.