CMA Foundation · Fundamentals of Business Mathematics and Statistics · Correlation and Regression
Six candidates are ranked by two interviewers. The sum of the squared differences in ranks is 14. What is Spearman's rank correlation coefficient?
The coefficient is 0.6. Using r = 1 − 6Σd²/[n(n²−1)] with n = 6 and Σd² = 14 gives 1 − 84/210 = 0.6, showing a moderately strong positive agreement between the two interviewers' rankings.
- A0.6Correct
- B0.4
- C-0.6
- D0.8
Explanation
With n = 6, n(n²−1) = 6 × 35 = 210. r = 1 − (6 × 14)/210 = 1 − 84/210 = 1 − 0.4 = 0.6. The value 0.4 results from forgetting to subtract the fraction from 1.
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