Hi, I am a first year stats grad student and I am taking a class on linear models. The book and lectures focus on the format of definition, proof, lemma, definition, proof, lemma etc. However, I cannot seem to find anywhere some practice problems where I could use these definitions before I actually take the tests. Some of the topics include estimability, gauss markov, aitken model, projection matrices, least square estimators, multivariate normal, spectral decomposition, cochran's thm and so on. If anyone knows of any books or websites or anything else that has some practice problems that use these definitions and formulas it'd be much appreciated!! Thank you in advance!!