Dr. Vance gathered quantitative data by tallying how often a sample of Year 12 and Year 13 students chose to use either a printed textbook or a digital tablet during their independent study sessions in the sixth form centre. Dr. Vance recorded the study medium of 25 Year 12 students and 25 Year 13 students over a morning study period. The data is displayed in Table 1.
Calculate the chi-squared value for this data by completing Table 2.
| Printed Textbook | Digital Tablet | Totals | |
|---|---|---|---|
| Year 12 | 14 | 11 | 25 |
| Year 13 | 6 | 19 | 25 |
| Totals | 20 | 30 | 50 |
| Student Group | Medium | Observed | Expected | O−EO - EO−E | (O−E)2(O - E)^2(O−E)2 | (O−E)2E\displaystyle \frac{(O - E)^2}{E}E(O−E)2 |
|---|---|---|---|---|---|---|
| Year 12 | Printed | 14 | 10.0 | |||
| Digital | 11 | 15.0 | ||||
| Year 13 | Printed | 6 | 10.0 | |||
| Digital | 19 | 15.0 | ||||
| χ2=\chi^2 =χ2= |
638 exam-style questions on Edexcel A Level Psychology Methods. Each one has a worked solution and a mark scheme showing where the marks go.