\begin{Schunk}
\begin{Sinput}
 ps5ts <- testSlopes(ps5)
\end{Sinput}
\begin{Soutput}
Values of x2 OUTSIDE this interval:
      lo       hi 
42.79481 45.87360 
cause the slope of (b1 + b2*x2)x1 to be statistically significant
\end{Soutput}
\end{Schunk}
