Question

having at least one 30 - minute warm - up session per week resulted in a drastic reduction in tears in the meniscus. in a study involving about 5000 adolescent boys hockey play one group was randomly assigned to warm up with a neuromuscular exercise session. this group had 57% fewer meniscus tears than the control group. complete parts a thro

a) is this an experiment or an observational study? explain why.
this is an experiment because random boys were assigned the specific exercise.

b) identify the treatments in this study. what is the response variable?
what are the treatments in this study?
a. being boy and not being boy
b. tearing one’s meniscus and not tearing one’s meniscus
c. having at least one 30 - minute neuromuscular warm - up exercise session per week and not having a warm - up session
d. playing hockey and not playing hockey
what is the response variable?
number of meniscus tears in each group
gender
whether or not the exercise was done
sport played

c) give one statistical advantage of using only boys from the specified country who played hockey in this study. choose the correct answer below.
a. the population is sufficiently large that a sample of 5000 adolescent boy hockey players does not appear to have been difficult to take.
b. participants with very similar backgrounds are more likely to follow the exercise routine together.
c. fixing the gender, sport, and nationality of the participants has produced very favorable results.
d. less variation in meniscus tears would be expected among players of the same gender in the same sport.

Explanation:

For part c, we analyze each option:

• Option A: The ease of sampling isn't the main advantage of restricting to this group.
• Option B: Similar backgrounds don't directly relate to following the routine.
• Option C: "Favorable results" is not the right way to describe the advantage of controlling variables.
• Option D: By fixing gender, sport, and nationality, we reduce variability in meniscus tears (since players of the same gender in the same sport are more homogeneous), which is a key statistical advantage in experiments.

Answer:

D. Less variation in meniscus tears would be expected among players of the same gender in the same sport.