The following table represents the probability distribution of a random variable $X$ for some $k \in Q$. Find the mean of $X$.
\begin{array}{|c|c|c|c|c|c|c|}
\hlineX=x & -2 & -1 & 0 & 1 & 2 & 3 \\
\hlineP(X=x) & 0.1 & k & 0.2 & 2 k & 0.3 & k \\
\hline
\end{array}