1. Regression equations only represent linear trends in data.
2. If the correlation between X and Y is larger than 0.5, then a linear equation is appropriate to describe the association.
3. To identify the presence of curvature, it can be helpful to begin by fitting a line and plotting the residuals from the linear equation.
4. The residual standard deviation se when fitting the model 1 / y = b0 + b1x has the same units as 1 / y.
5. The reciprocal transformation is commonly applied to rates, such as miles per gallon or dollars per square foot.