The Wilcoxon test was used on 18 pairs of data.The total of the ranks (T)were computed to be 111 (for + ranks)and 60 (for - ranks).The z value for this test is ____.
A)-1.11
B)-0.05
C)-0.07
D)0.033
E)2.22

Question

Quizplus · Accepted Answer

The z value for the Wilcoxon test is calculated as (T+ - T-) / sqrt(n(n+1)/2), where T+ is the sum of the ranks for the positive differences, T- is the sum of the ranks for the negative differences, and n is the number of pairs of data. In this case, T+ = 111, T- = 60, and n = 18, so the z value is (111 - 60) / sqrt(18(18+1)/2) = -1.11.

The Wilcoxon Test Was Used on 18 Pairs of Data