12.5 Linear Regression Models and Confidence Intervals

random residuals condition

there should be no evidence of patterns, trends, or clumping when looking at the residuals plot - part of the independence assumption

does the plot thicken? condition

the spread around the regression line should be nearly constant - part of the equal variance assumption

nearly normal condition

the data in the distribution should resemble a normal model - part of the normal errors assumption

independence assumption

the errors in the underlying regression model should be independent of each other

randomization condition

the individuals in the sample are randomly selected - part of the independence assumption

straight enough condition

the scatterplot of y against x should have a linear form - part of the linear assumption