A specialty coffee chain evaluates its top 10 baristas based on their internal seniority index (where 1 is the most senior) and their performance in a recent quality control assessment.
| Barista | Seniority Index | Regional Awards | Quality Score |
|---|---|---|---|
| A | 1 | 4 | 82 |
| B | 2 | 2 | 95 |
| C | 3 | 2 | 70 |
| D | 4 | 1 | 88 |
| E | 5 | 2 | 55 |
| F | 6 | 0 | 84 |
| G | 7 | 1 | 62 |
| H | 8 | 0 | 45 |
| I | 9 | 0 | 48 |
| J | 10 | 0 | 75 |
Explain how a researcher should handle the tied values in the 'Regional Awards' column when calculating Spearman's rank correlation coefficient.
Using the 'Quality Score' data (where the highest score is ranked 1), calculate Spearman's rank correlation coefficient, rsr_srs, between the seniority index and the quality score rank.
Test, at the 5% level of significance, whether there is evidence of a positive correlation between seniority and performance quality. State your hypotheses and critical value clearly.
Determine the largest level of significance (from standard statistical tables for n=10n=10n=10) that would lead to a conclusion that there is no evidence of a positive correlation. State the corresponding critical value.
Practise Edexcel A Level Maths Regression, Correlation and Hypothesis Testing with exam-style questions for A Level Maths. 202 questions covering Exponential Models, Measuring Correlation, and Hypothesis Testing for Zero Correlation, matched to the Edexcel A Level Maths (9MA0) 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.
