Final answer:
A scatter plot indicates a positive correlation when both variables increase together, a negative correlation when one variable increases while the other decreases, and zero correlation when there is no discernible trend.
Step-by-step explanation:
To correctly complete the sentence regarding the type of association indicated by a scatter plot, you must understand the concepts of positive correlation, negative correlation, and zero correlation. A scatter plot showing a positive correlation means the variables move in the same direction: as one increases, so does the other. Conversely, a negative correlation shows that the variables move in opposite directions: as one increases, the other decreases. A scatter plot with zero correlation will have no discernible trend or pattern, indicating no linear relationship between the variables. The correlation coefficient, denoted by 'r', quantifies the strength and direction of this relationship. A value of 0 < r < 1 signifies a positive correlation, -1 < r < 0 indicates a negative correlation, and r = 0 signifies no correlation.