STAT 100 Lecture Notes - Lecture 7: Dependent And Independent Variables, Scatter Plot, Negative Relationship
Document Summary
First goal: to establish if a possible linear relationship between the 2 variables. 2nd goal: formulate a line that best represents or fits our data. To establish the relationship we can do it : visually with a scatterplot a 2 dimensional graph. X axis explanatory variable also called predictor variable: height. Positive relationship: line would increase left to right. Y axis- response variable or outcome variable: weight. Response: as x increased, y decreased. Line would decrease left to right: negative slope. Ex 2: x weight, y hair length, not really a relationship. No change graph line would be horizontal. Using the visual we can then do the next part: numerically using a correlation between the 2 variables. Correlation to numerically represent a linear relationship between 2 quantitative variables. Our notation for the sample correlation is the letter r read r . Correlation measures the strength and direction of the linear relationship.
