Definitions
What kind of data involves two variables?
Bivariate Data
What's the mathematical symbol for correlation?
r (rho)
What visual tool displays the relationship between two variables?
Scatterplot
What's the equation to find the slope of a best-fit line?
Least Squares Regression (LSR)
What does a positive correlation tell you?
Positive Correlation - Variables tend to move in the same direction (as one increases, the other increases, or vice versa).
What does a correlation coefficient of 0 indicate?
No correlation (r = 0)
What are the vertical distances between data points and the best-fit line called?
Residuals
What's the most common method for finding the best-fit line?
Slope of the best-fit line
What does a negative correlation tell you?
Variables tend to move in opposite directions (as one increases, the other decreases).
How can you tell if a correlation is statistically significant?
Statistically significant correlation - Requires additional statistical tests beyond the correlation coefficient.
What does a random scatter of points suggest about the relationship?
Random Scatter - No apparent relationship between the variables.
What are the limitations of using a linear regression model?
Limitations of Linear Regression - Assumes a linear relationship, may not be suitable for non-linear patterns.
What's the difference between correlation and causation?
Correlation vs. Causation - Correlation describes a relationship, but it doesn't necessarily mean one variable causes the change in the other.
What does the coefficient of determination (r²) represent?
Coefficient of Determination (r²) - Represents the proportion of variance in one variable explained by the other variable (expressed as a percentage).
How can outliers affect the best-fit line?
Outliers - Can significantly affect the slope and position of the best-fit line.
What type of regression model is best for non-linear relationships?
Non-linear Regression Model (e.g., polynomial, exponential)