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Chapter 10
Question 4
Spearman's rank correlation
Calculate Spearman’s rank correlation coefficient for the following data, ranking
the best scores as 1 through to the worst as 5.
chemistry score maths score
Bob 43% 55%
Jim 61% 57%
Ash 57% 88%
Zak 76% 59%
Jen 85% 96%
6∑d 2
R = 1 –
2
n(n 1)
Chemistry Maths
2
chemistry score maths score rank rank d d
Bob 43% 57% 5 5 0 0
Jim 61% 59% 3 4 –1 1
Ash 57% 88% 4 2 2 4
Zak 76% 71% 2 3 –1 1
Jen 85% 96% 1 1 0 0
∑d 2 6
R = 1 – (6 × 6)/[5 × (25 – 1)]
R = 1 – 36/120 = 0.7
156
