\begin{Schunk}
\begin{Sinput}
 ndf2 <- data.frame(GRIP = plotSeq(dat$GRIP, 5))
 ndf2$pred2 <- predict(mod1, ndf2)
 ndf2
\end{Sinput}
\begin{Soutput}
  GRIP    pred2
1   29 35.64132
2   69 38.28491
3  109 40.92850
4  149 43.57209
5  189 46.21569
\end{Soutput}
\end{Schunk}
