Question

types of statistical studies
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: What type of a statistical study did the researchers use?

The researchers prepared a survey questionnaire and had all farms in Great Britain fill it out. A sample study involves collecting data from a sample (here, all farms in GB as the sample) through surveys, etc. An experiment would involve manipulating variables, and an observational study is just observing without intervention. Since they used a survey with a sample (all farms), it's a sample study.

The result shows that on farms where cows were named, milk yield was higher. This indicates a positive correlation (relationship) between calling British cows by name and their milk yield. Option A and B imply causation (saying naming "causes" more milk), but correlation doesn't mean causation. Option D mentions "the cows' milk yield" generally, but the study is about British cows. So option C is correct as it states a positive correlation between calling British cows by name and their milk yield.

Answer:

A. Sample study

Second Question: What valid conclusions can be made from this result?