I have been trying to fit a trend line using pgf plot for my data and unfortunately can't seem to hit the right spot with the code. I have looked in the manual for examples of linear regression and unfortunately it has been of no help. I already know the equation of the line from excel which calculates it to be $y=21208x+346.68$. Can anyone think of how I can fix this? To top it off now my code presented below is not correct!
\documentclass{article}
\usepackage{textcomp}
\usepackage{pgfplots}
\usepackage{pgfplotstable}
\pgfplotsset{compat = newest}
\begin{document}
\begin{tikzpicture}
\begin{axis}[
title={BET Plot of Mesoporous Solid},
xlabel={Relative pressure $P/P_0\times 10 ^{-3}$},
ylabel={$\frac{P/P_0}{V(1-P/P_0)}$ [$m^{-3}$]},
xmin=0, xmax=250,
ymin=0, ymax=5000,
xtick={0,50,100,150,200,250},
ytick={0,1000,2000,3000,4000,5000},
legend pos=north west,
ymajorgrids=true,
grid style=dashed,
]
\addplot[
color=black,
mark=square,
]
coordinates {
(29.9025,905.43528)(63.7920,1716.5088)(97.6815,2471.0442)(122.6003,2977.7455)(145.5255,3470.4408)(174.4313,4060.0613)(194.3663,4448.5030)(208.3208,4708.7817) };
\addplot[
\addplot table[y={create col/linear regression={y=Y}}]{
(29.9025,905.43528)(63.7920,1716.5088)(97.6815,2471.0442)(122.6003,2977.7455)(145.5255,3470.4408)(174.4313,4060.0613)(194.3663,4448.5030)(208.3208,4708.7817) };
\end{axis}
\end{tikzpicture}
\end{document}