STATS 13 Chapter Notes - Chapter 10: Total Variation, Dependent And Independent Variables, Null Hypothesis
Document Summary
Section 10. 1: summarizing the relationship between two quantitative variables using the. Scatterplot: shows the two values for each observational unit. Positive: above average values of one variable correspond to above average values of the other variable. Negative: above average values of one variable are associated with below average values of the other. Form: linear pattern or some other complicated pattern. Strength: how closely the points follow a pattern. Strong association: value of 1 variable can be accurately predicted from the other. Unusual observations: do not follow the overall pattern. Correlation coefficient (r): measures the strength and the direction of a linear association. Close to -1 or 1 high correlation. No resistant to extreme values r = 0 no correlation. Are far to the right or left of the graph (extreme values for the explanatory variable) Outliers may or may not be influential. Are unusual in terms of the combination of values.
