A Weight-Lifting Coach Claims That a Weight-Lifter Can Increase Strength $$\alpha$$

Multiple Choice

A weight-lifting coach claims that a weight-lifter can increase strength by taking vitamin E. To test the theory, the coach randomly selects 9 athletes and gives them a strength test using a bench press. The results are listed
Below. Thirty days later, after regular training supplemented by vitamin E, they are tested again. The new
Results are listed below. Find the critical value for a Wilcoxon signed-rank test to test the claim that the vitamin
E supplement is effective in increasing the athletesʹ strength. Use $$\alpha$$ = 0.05. $$\begin{array} { l c c c c c c c c c } \hline \text { Athlete } & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 \\\hline \text { Befor } & 230 & 233 & 247 & 202 & 201 & 193 & 232 & 239 & 198 \\\text { After } & 240 & 238 & 247 & 200 & 208 & 208 & 237 & 234 & 203 \\\hline\end{array}$$

A) 6
B) 4
C) 2
D) 3