linear regression

1. Simple linear regression is about building a line that models the relationship between two quantitative variables.
   
2. Correlation coefficients are a measure that can inform you about the strength and direction of a linear relationship.
   
3. The most common way to visualize simple linear regression is using a scatterplot.
   
4. A line is defined by an intercept and slope, which you found using the statsmodels library in Python.