\begin{tabular}{@{}l*{2}{l}@{}}
\hline
  &\multicolumn{1}{l}{M1  }\tabularnewline
 &\multicolumn{1}{l}{Estimate}\tabularnewline
 &\multicolumn{1}{l}{(S.E.)}\tabularnewline
 \hline
 \hline
  (Intercept) & 951.121*** \tabularnewline
 &(143.784)\tabularnewline
  oldx & 126.882*** \tabularnewline
 &(  9.866)\tabularnewline
 \hline
 N&\multicolumn{1}{l}{100} \tabularnewline
 RMSE&282.609\tabularnewline
 $R^2$&0.628\tabularnewline
 \hline
\hline
 
 \multicolumn{2}{l}{  ${*  p}\le 0.05$${*\!\!*  p}\le 0.01$${*\!\!*\!\!*  p}\le 0.001$}\tabularnewline
 \end{tabular}