Question

british researchers were interested in the relationship between farmers’ approach to their cows and the cows’ milk yield. they prepared a survey questionnaire regarding the farmers’ perception of the cows’ mental capacity, the treatment they give to the cows, and the cows’ yield. the survey was filled by all the farms in great britain.

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

after analyzing their results, they found that on farms where cows were called by name, milk yield was 258 liters higher on average than on farms where this was not the case.

what valid conclusions can be made from this result?
choose 1 answer:
a the result suggests that naming a cow will cause her to produce more milk.
b naming a british cow will cause her to produce more milk.
c the result suggests that there is a positive correlation between calling british cows by name and the cows’ milk yield.
d the result suggests that there is a positive correlation between calling cows by name and the cows’ milk yield.

Explanation:

First Question (Type of Statistical Study)

The researchers prepared a survey questionnaire and collected data from all farms in Great Britain about farmers' approach, perception, and cows' yield. This is a sample study as they are using data from a sample (all farms in GB, which is a sample of all possible farms) to study the relationship. An experiment would involve manipulating a variable, and an observational study is more about observing without intervention, but here it's a survey-based sample study.

Correlation means a relationship between two variables, not causation. The result shows that on farms where cows were named, milk yield was higher, so there's a positive correlation between calling British cows by name and their milk yield. Options A and B imply causation (using "cause") which can't be concluded from this observational/survey data. Option D is incorrect as it's about British cows (the study is about British cows).

Answer:

A. Sample study

Second Question (Valid Conclusion)