\begin{knitrout}
\definecolor{shadecolor}{rgb}{0.969, 0.969, 0.969}\color{fgcolor}\begin{kframe}
\begin{alltt}
\hlstd{fit.psr.1}\hlkwb{<-}\hlkwd{lm}\hlstd{(Y}\hlopt{~}\hlstd{Z}\hlopt{+}\hlstd{ps.fit.c)}
\hlkwd{summary}\hlstd{(fit.psr.1)}
\end{alltt}
\begin{verbatim}
+ 
+ Call:
+ lm(formula = Y ~ Z + ps.fit.c)
+ 
+ Residuals:
+      Min       1Q   Median       3Q      Max 
+ -2.59541 -0.26342  0.07312  0.31082  2.69878 
+ 
+ Coefficients:
+             Estimate Std. Error t value            Pr(>|t|)    
+ (Intercept)  1.58112    0.07007   22.57 <0.0000000000000002 ***
+ Z           -2.05087    0.03772  -54.37 <0.0000000000000002 ***
+ ps.fit.c     4.78344    0.11320   42.26 <0.0000000000000002 ***
+ ---
+ Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
+ 
+ Residual standard error: 0.5405 on 997 degrees of freedom
+ Multiple R-squared:  0.7835,	Adjusted R-squared:  0.7831 
+ F-statistic:  1804 on 2 and 997 DF,  p-value: < 0.00000000000000022
\end{verbatim}
\end{kframe}
\end{knitrout}