Question

a research institute interested in factors that can either cause or prevent cardiovascular disease conducted a long - term study of the 5209 people of framingham, massachusetts. the study included extensive physical examinations and lifestyle interviews performed every 2 years, which were analyzed for common patterns related to cardiovascular disease development.

what type of statistical study did the researchers use?
choose 1 answer:
a sample study
b experiment
c observational study

the researchers found a negative association among males between the amount of daily physical activity and the occurrence of cardiovascular diseases.

what valid conclusions can be made from this result?
mark the most suitable choice.
choose 1 answer:
a the result suggests that there is a positive correlation between high physical activity and low risk of cardiovascular disease among the people of framingham.
b the result suggests that males from framingham who work out 2 hours every day dont have any cardiovascular risk.
c the result suggests that an increase in physical activity may cause a reduction in the risk of cardiovascular disease.
d the result suggests that there is a positive correlation between high physical activity and low risk of cardiovascular disease among males in framingham.

Explanation:

First Sub - Question (Type of Statistical Study)

A sample study involves analyzing a sample (here, 5209 people from Framingham) to draw conclusions about a larger population. An experiment would involve manipulating variables, which isn't done here. An observational study is broader, but this is a sample (a subset) of the population being studied. So the correct type is a sample study.

A negative association between physical activity and cardiovascular disease occurrence means as physical activity increases, the risk of cardiovascular disease decreases (or vice - versa). Option A: A positive correlation is wrong (it's negative). Option B: Saying they “don't have any” risk is extreme and not supported. Option C: Since more physical activity is associated with less disease, increasing physical activity may reduce the risk (this is a valid inference from the negative association). Option D: Positive correlation is wrong (it's negative).

Answer:

A. Sample study

Second Sub - Question (Valid Conclusion)