\begin{Schunk}
\begin{Sinput}
 m2 <- lm(y ~ x1*x2, data=dat)
 summary(m2)
\end{Sinput}
\begin{Soutput}
Call:
lm(formula = y ~ x1 * x2, data = dat)

Residuals:
    Min      1Q  Median      3Q     Max 
-634.81 -173.75  -17.76  160.99  715.48 

Coefficients:
             Estimate Std. Error t value Pr(>|t|)   
(Intercept) -424.2604   379.0010  -1.119  0.26364   
x1             6.5226     7.2091   0.905  0.36613   
x2             7.3553     7.3616   0.999  0.31833   
x1:x2          0.3922     0.1387   2.829  0.00491 **
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Residual standard error: 257.2 on 396 degrees of freedom
Multiple R-squared:  0.7032,	Adjusted R-squared:  0.7009 
F-statistic: 312.7 on 3 and 396 DF,  p-value: < 2.2e-16
\end{Soutput}
\end{Schunk}
