documentclass[12pt]{article}
%usepackage{setspace}
usepackage{tabularx}

begin{document}

begin{table}
 renewcommand{arraystretch}{1.3}
caption{Summary Statistics}
centering
begin{tabularx}{1textwidth}{l c c c c  }
hlinehline
Variable & Mean & Median & Pct 25 & Pct 75 \
hline
Log Price & -1.023& -1.021&-1.206 & -.844 \
Log Quantity &1.23 &1.23 &1.13 &1.33 \
hlinehline
end{tabularx}
label{table:summary}
end{table}

end{document}