Use the Wilcoxon signed-ranks test to test the claim that the matched pairs have differences that come from a population with a median equal to zero.

14) Use Wilcoxon's signed-ranks test and a 0.05 significance level to test the claim that the population of differences between the mathematics and verbal scores has a median of zero. State the test stat and the critical value:

Mathematics      347 440 327 371 427 271 377 398 385
Verbal                285 440 243 456 340 349 294 322 425
Differences          62     0   84 -85    87 -78   83    76  -40
Abs Differences   62     0   84  85    87  78   83    76  40
Rank

A) Test statistic T = 12. Critical value: T = 8.    B) Test statistic T = 12. Critical value: T = 4.
C) Test statistic T = 12. Critical value: T = 5.    D) Test statistic T = 24. Critical value: T = 3.