\tikzstyle{hidden_neuron}=[circle,draw=red!50,fill=orange!10,thick,minimum size=.2mm]
\tikzstyle{input_neuron}=[circle,draw=blue!50,fill=blue!10,thick,minimum size=1mm]
\tikzstyle{output_neuron}=[circle,draw=green!50,fill=green!20,thick,minimum size=1mm]
\tikzstyle{input}=[circle,draw=black!50,fill=black!20,thick,minimum size=.2mm]
%\vspace{-0.3in}
\begin{center}

\begin{tikzpicture}
		\node  (a) at (3,4) {\huge{C}} ;
		\node  (b) at (1,2) {\huge{$X_1$}} ;
		\node  (c) at (2.5,2) {\huge{$X_2$}} ;
		\node  (d) at (5.2,2) {\huge{\ldots}} ;
		\node  (e) at (4,2) {\huge{$X_3$}} ;
		\node  (f) at (6,2) {\huge{$X_n$}} ;
		\draw [->, line width=0.3mm] (a) -- (b);
		\draw [->, line width=0.3mm] (a) -- (c);
		\draw [->, line width=0.3mm] (a) -- (e);
		\draw [->, line width=0.3mm] (a) -- (f);
\end{tikzpicture}
\end{center}