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?
mark the most suitable choice.
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, distributed it to farms in Great Britain, and analyzed the responses (farmers’ perception, cows’ mental capacity, and cows’ yield). An observational study involves observing and collecting data without intervening (like an experiment). A sample study isn't a standard study type here, and an experiment would involve manipulating a variable (they didn't manipulate, just surveyed). So it's an observational study.

The study found a difference in milk yield between farms where cows were named and where they weren't. Correlation means a relationship, not causation. Options A and B imply causation ("cause"), which can't be concluded from observational data. Option D correctly states a positive correlation between calling cows by name and milk yield (since named cows had higher yield on average).

Answer:

C. Observational study

Second Question (Valid Conclusion)