Answer:
- <em>B. experimental group: athletes wearing the new shoes; control group: athletes not wearing the new shoes.</em>
<em />
Explanation:
The objective of the <em>experiment</em> is to determine whether the<em> new brand of gym shoes</em> increase <em>athlete's vertical leaps</em>.
Then, your experiment shall have:
- The independent variable, i.e. a variable that you can manipulate and test to determine how it changes the dependent variable. In this case it is the shoes.
- The dependent variable is how high the athletes jump.
- Control group: the group with which you want to compare to determine whether it is true or not that the new brand of gym shoe increase athlete's vertical leaps.
Then, you can test the two groups.
- The <em>experimental group</em>, which is the<em> athletes wearing the new shoes</em>, and
- The <em>control group</em>, which is the <em>athletes not wearing the new shoes</em>.
That is described by the statement <em>B. experimental group: athletes wearing the new shoes; control group: athletes not wearing the new shoes.</em>
Note that, in order for the results not be biased, the two groups should be selected randomly and represent average athletes. It is not correct to select elite athletes or non average athletes for either of the groups.
Then, you will compare the marks of the two groups and, if the difference in the heights of the jumps is significatively in favor of the new shoes, you can back up the claim of the new brand of gym shoes.