Which one of the following best describes a positive correlation between two variables as displayed on a Scatter Diagram?

A positive correlation between two variables on a scatter diagram indicates that as one variable increases, the other variable also tends to increase. This relationship demonstrates a direct association where an upward trend in the data points is observed when plotted.

In the correct option, it is stated that as the values of the independent variable increase, the corresponding values of the dependent variable also increase. This means that there is a consistent pattern of both variables moving in the same direction, which is a hallmark of positive correlation.

Highlighting the reasons for the other choices can provide more context. The first option suggests a negative relationship, as it reflects a scenario in which an increase in the independent variable leads to a decrease in the dependent variable. The third option describes a situation where the dependent variable first increases and then decreases, which would imply that there is a maximum value reached before a decrease, indicating a different kind of relationship than simple positive correlation. Lastly, the fourth option describes a non-linear pattern where the dependent variable decreases to a minimum before increasing, suggesting a more complex relationship rather than a straightforward positive correlation.

Thus, the positive correlation indicated by the correct answer is characterized by both variables rising together, reinforcing the concept of direct proportionality in a scatter diagram.