\documentclass[a5paper]{article}
\usepackage[margin=5mm]{geometry}
\usepackage{xint-regression}
\begin{document}
\def\LLX{83,71,64,69,69,64,68,59,81,91,57,65,58,62}%
\def\LLY{183,168,171,178,176,172,165,158,183,182,163,175,164,175}%
%default output
\xintLINreg{\LLX}{\LLY}%
$a \approx \linrega$ and $b \approx \linregb$ \\
$r \approx \linregr$ and $r^2 \approx \linregrr$
\end{document}