I have a homework problem that asks me to fit a one way ANCOVA model to a set of data (which I feel comfortable with). The model is represented as
yij = μi + γzij + eij
where i indicates temperature and j indicates tree.
Then I am asked to replace the temperature effects with a quadratic polynomial:
yij = Β0 + Β1Ti + Β2Ti2 + γzij + eij
This is where things get confusing for me. Conceptually I don't understand what is going on so I'm hoping that someone can explain it to me a little better than the one line in my textbook. Thanks!
Also this is an excerpt about the data being used in this problem with a portion of the table: