You are performing the Wilcoxon rank sum test. The 10th through 12th values in an ordered array of pooled sample data all equal $100, while the 9th value is less than $100 and the 13th value is more than $100. What are the appropriate ranks for the three $100 values?
A) 9, 9, 9
B) 10, 10, 10
C) 11, 11, 11
D) 12, 12, 12

Question

Quizplus · Accepted Answer

The appropriate ranks for the three $100 values should be the average of the ranks they would have if there were no ties. Since there are 14 values in total, the midpoint rank is 7.5. The 9th value has rank 9 and the 13th value has rank 13, which means the three $100 values would have ranks 10, 11, and 12. Since these values are tied, their average rank is (10+11+12)/3 = 11, so the answer is C.

You Are Performing the Wilcoxon Rank Sum Test