A Weight-Lifting Coach Claims That Weight-Lifters Can Increase Their Strength $\alpha$

question 83

Essay

A weight-lifting coach claims that weight-lifters can increase their strength by taking a certain supplement. 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 using the supplement, they are tested again.
The new results are listed below. Test the claim that the supplement is effective in increasing the athletesʹ
strength. Assume the samples are random and dependent, and the populations are normally distributed. Use $\alpha$ = 0.05. $$\begin{array} { l | c c c c c c c c c } \text { Athlete } & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 \\\hline \text { Before } & 215 & 240 & 188 & 212 & 275 & 260 & 225 & 200 & 185 \\\hline \text { After } & 225 & 245 & 188 & 210 & 282 & 275 & 230 & 195 & 190\end{array}$$

---

Definitions:

Negative Feelings

This term encompasses a range of emotions such as sadness, anger, and fear, which are often unpleasant and associated with negative thoughts and experiences.

Subjective Well-Being

Subjective Well-Being is the self-perceived feeling of happiness or satisfaction with one’s life. It is a key component of positive psychology.

Work Satisfaction

The contentment a person feels regarding their job and its various aspects.