**Learning objectives**

- Interpret data sets as collections of vectors
- Work with linear combinations of vectors in algebraic and geometric forms
- Interpret systems of linear equations in the language of vectors
- Explain inconsistency of linear equations in geometric language
- Express linear combinations of vectors using matrix multiplication

**Before class**

- Make a properly labeled scatterplot (with a title) of the Keeling CO2 data
- Read introduction to linear models
- Read chapters 1, 2 and 3 of the Linear Algebra Reader
- Consult the main points of the lesson.

**In class**

- Answer questions about CO2 project
- Discuss residuals for a data based model, using StartR
- Begin linear algebra