Skip to content
Open
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion public/latex_notes/unit4/unit4.tex
Original file line number Diff line number Diff line change
Expand Up @@ -284,7 +284,7 @@ \subsection{Relationship between single and two predictor regression coefficient
Instead, $\epsilon'$ absorbs the variation in $Y$ that is correlated with $X_2$ but unaccounted for by $X_1$.
Because $X_1$ and $X_2$ are generally correlated, part of the systematic variation explained by $X_2$ is treated as noise in the single-predictor model. Rather we have
\begin{equation}
{\rm var}(\epsilon') = {\rm var}(Y|X_1) = {\rm var}(\beta_1 X_1 + \beta_2 X_2 + \epsilon|X_1) = \beta_1^2{\rm var}(X_2|X_1) + \sigma_{\epsilon}^2 > \sigma_{\epsilon^2}
{\rm var}(\epsilon') = {\rm var}(Y|X_1) = {\rm var}(\beta_1 X_1 + \beta_2 X_2 + \epsilon|X_1) = \beta_2^2{\rm var}(X_2|X_1) + \sigma_{\epsilon}^2 > \sigma_{\epsilon^2}
\end{equation}
hence
\[
Expand Down