A best-fit line is a straight line that represents the trend or relationship between two variables in a scatter plot. It is determined by minimizing the overall distance between the line and all the data points.
The slope of a best-fit line represents how steep or flat the line is. It indicates how much one variable changes for every unit change in another variable.
Correlation Coefficient: The correlation coefficient measures the strength and direction of the linear relationship between two variables. It ranges from -1 to 1, where -1 indicates a perfect negative correlation, 0 indicates no correlation, and 1 indicates a perfect positive correlation.
Residuals: Residuals are the vertical distances between each data point and the corresponding point on the best-fit line. They represent how far off each data point is from what would be predicted by the best-fit line.