Exercise 16.18 asks for the rank sum for Central Asia.
reggdp
What is the rank sum for European developing countries? The ranks of 20 observations always add to 210. Do your two sums add to 210?
Repeat the previous exercise using the the rank sum for European countries. Show that you obtain exactly the same -value. That is, your choice between the two possible ’s does not affect the results of the Wilcoxon test.