A look at transformations in the context of simple linear regression. I look at two examples where taking a transformation (applying a function to the response and/or explanatory variables) can help to satisfy the assumptions of the simple linear regression model. The brain and body weight data is from: Sacher, G.A. Staffeldt, E. (1974). Relation … Read more
I discuss confidence intervals for the mean of Y and prediction intervals for a single value of Y for a given value of X in simple linear regression. I discuss the form of the confidence interval for the mean and prediction interval for a single value and their standard errors. The data used is estimated … Read more
A brief introduction to leverage and influence in simple linear regression. This video is about the basic concepts, and only briefly mentions numerical measures of leverage and influence at the end.
A look at the relationship between the pooled-variance t test and simple linear regression. I illustrate how the pooled-variance t test can be done as a regression, by declaring an appropriate indicator variable. The Cairo traffic police officer data is simulated data with the same summary statistics as found in: Kamal, A., Eldamaty, S., and … Read more