From 6029c66b50df2632d33fa251d76172de5e60cc39 Mon Sep 17 00:00:00 2001 From: zleyyij Date: Fri, 15 Dec 2023 12:58:31 -0700 Subject: [PATCH] vault backup: 2023-12-15 12:58:31 --- education/statistics/Correlation and Regression.md | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/education/statistics/Correlation and Regression.md b/education/statistics/Correlation and Regression.md index bb9882c..421b14f 100644 --- a/education/statistics/Correlation and Regression.md +++ b/education/statistics/Correlation and Regression.md @@ -71,4 +71,7 @@ https://www.thoughtco.com/how-to-calculate-the-correlation-coefficient-3126228 - Just because a relationship exists between $x$ and $y$ *does not* mean that changes in $x$ *cause* changes in $y$. - If the graph is given to you already set up, you already know the response and explanatory variables. - The $\sigma$ line will always always have a slope of: -$$\frac{\sigma_x}{\sigma_y}$$ \ No newline at end of file +$$\pm \frac{\sigma_y}{\sigma_x}$$ +- The SD line always passes through the averages for each axis. +- Someone who is *exactly on* the SD line is the same number of SDs above or below +Given a scatter diagram where the average of each set lies on the point $(75, 70)$, with a $\sigma_x$ of 10 and a $\sigma_y$ of 12, you can graph the SD line by going up $\sigma_y$ and right $\sigma_x$, then connecting that point (in this example, $(85, 82)$) with the mean points. \ No newline at end of file