The relationship between population size and the number of
restaurants or wine cellars in each of the Priorat study villages can be
presented as a scattergraph and tested using Spearman's
Rank Correlation Coefficient.
Restaurants and Wine Cellars in
Priorat
Village
Population
Rank
Pop
Restaurants
Rank
Rest
d˛
Cellars
Rank
Cell
d˛
Pradell
169
1
1
1
Gratallops
253
5
18
18
Lloar
113
1
0
0
Torroja
147
1
8
8
Porrera
477
2
14
14
Sd˛
Calculate the coefficient (r˛) using the formula below. The answer will
always be between 1.0 (a perfect positive correlation) and -1.0 (a perfect
negative correlation).
When written in mathematical notation the Spearman Rank formula
looks like this :