British researchers were interested in the relationship between farmers' approach to their cows and 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. 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 when this was not the case. All right, so they're making a connection between two variables. One was whether cows called by name, whether cows named, all right, whether cows named, and this would be a categorical variable because for any given farmer, it's gonna be a yes or a no that the cows are named. And so they're trying to form a connection between whether the cows are named and milk yield.