Final answer:
The correlation coefficient measures the strength of the linear association between x and y.
Step-by-step explanation:
The correlation coefficient, r, measures the strength of the linear association between x and y. The variable r has to be between -1 and +1. When r is positive, x and y tend to increase and decrease together. When r is negative, x increases and y decreases, or the opposite occurs: x decreases and y increases. The coefficient of determination, r², is equal to the square of the correlation coefficient. When expressed as a percentage, r² represents the percentage of variation in the dependent variable, y, that can be explained by variation in the independent variable, x, using the regression line.