Choose the one alternative that best completes the statement or answers the question.
-A pharmaceutical company wishes to test a new drug with the expectation of weight reduction. Ten subjects are randomly selected and their weights are recorded. The subjects were placed on the drug for a period of 6 months, after which their weights were recorded again. The results are listed below. (All units are pounds.) Use the Wilcoxon signed-ranks test to find the test statistic T to test the company's hypothesis that the drug reduces weight. Use $\alpha = 0.05$.
$\begin{array}{lcccccccccc}
\hline \text { Subject } & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 & 10 \
\hline \text { Before } & 253 & 254 & 255 & 201 & 258 & 170 & 241 & 266 & 270 & 248 \
\text { After } & 238 & 249 & 263 & 191 & 253 & 170 & 211 & 248 & 268 & 233
\end{array}$
A) 4
B) 7.5
C) 41
D) $5.5$

Question

Quizplus · Accepted Answer

The test statistic for the Wilcoxon signed-ranks test is the sum of the ranks of the positive differences. In this case, the positive differences are: 15, 5, 8, 10, 5, 0, 30, 18, 2, 15. The sum of these ranks is 41.

Choose the One Alternative That Best Completes the Statement or Answers