What does it mean if the slope of a regression line is positive?

A positive slope in a regression line indicates a direct relationship between the two variables being analyzed. Specifically, if one variable increases, the other variable also increases. This suggests that there is a consistent pattern in the data where higher values of one variable correspond to higher values of the other variable. This is a foundational concept in statistics, as it allows researchers to predict the behavior of one variable based on changes in another, making it crucial in regression analysis.

In contexts such as real-world applications, a positive slope can imply various practical relationships, such as how an increase in study time might correlate with higher exam scores, illustrating the importance of understanding direct relationships in data analysis.