Theory question 105
StatisticsTwo panel of judges, X and Y, rank 8 brands of cooking oil as follows:
Cooking oil type: A, B, C, D, E, F, G, H
X: 8, 5, 1, 7, 2, 6, 3, 4
Y: 6, 3, 4, 8, 5, 7, 1, 2
Calculate the Spearman's rank correlation coefficient.
Show the model answer
Model answer
d = X − Y: 2, 2, −3, −1, −3, −1, 2, 2; Σd² = 36.
ρ = 1 − 6(36)/(8 × 63) = 1 − 216/504 ≈ 0.57.
Explanation
The values are already ranks, so subtract directly.