For a given set of 12 ranked data values,the sum of the squared differences is 63.18. What is Spearman's coefficient of rank correlation for the data?
A)+0.7791
B)−0.7791
C)+0.2209
D)−0.2209

Question

Quizplus · Accepted Answer

Spearman's coefficient of rank correlation, denoted as $r_s$, is calculated using the formula $r_s = 1 - \frac{6 \sum d_i^2}{n(n^2 - 1)}$, where $d_i$ is the difference between the ranks of each observation, and $n$ is the number of observations. Substituting the given values ($\sum d_i^2 = 63.18$ and $n = 12$) into the formula gives $r_s = 1 - \frac{6 \times 63.18}{12(12^2 - 1)} = +0.7791$.

For a Given Set of 12 Ranked Data Values,the Sum