3. A random variable \( X \) has the following probability distribution
\begin{tabular}{|c|c|c|c|c|}
\hline\( X \) & 2 & 5 & 6 & 7 \\
\hline\( P(X) \) & \( \frac{1}{10} \) & \( X \) & \( \frac{3}{10} \) & \( \frac{4}{10} \) \\
\hline
\end{tabular}
Find the mean and variance of X
a) \( 5.4,2 \)
b) \( 5.8,2.16 \)
c) \( 5.8,2 \)
d) none of these
