Linear regression

What the problems look like

A few statements from this skill. Answers, hints and worked solutions live in the practice session.

1. Warm-up

   For a bivariate data set, $S_{xx} = 25$, $S_{yy} = 16$, and $S_{xy} = 14$. Compute the correlation coefficient $r = \dfrac{S_{xy}}{\sqrt{S_{xx}S_{yy}}}$, rounded to 2 decimal places.

2. Warm-up

   For a bivariate data set, $S_{xx} = 4$, $S_{yy} = 81$, and $S_{xy} = -14$. Compute the correlation coefficient $r = \dfrac{S_{xy}}{\sqrt{S_{xx}S_{yy}}}$, rounded to 2 decimal places.

3. Warm-up

   For a bivariate data set, $S_{xx} = 81$, $S_{yy} = 64$, and $S_{xy} = -42$. Compute the correlation coefficient $r = \dfrac{S_{xy}}{\sqrt{S_{xx}S_{yy}}}$, rounded to 2 decimal places.

Problems shown under their original terms: Generated (template, solver-computed).