\begin{Schunk}
\begin{Sinput}
 m1psts <- testSlopes(m1ps)
\end{Sinput}
\begin{Soutput}
Values of x2 INSIDE this interval:
       lo        hi 
 20.30582 122.54847 
cause the slope of (b1 + b2*x2)x1 to be statistically significant
\end{Soutput}
\end{Schunk}
