An analog signal with a maximum amplitude of 5 volts is sampled 15 times at intervals of 1 $\mathrm{ms}$ by a 4-bit A/D converter. The values are shown below. Reconstruct the analog signal and comment on the accuracy of the plot. Identify two ways of obtaining a better digital representation of the original analog signal.
$$
\begin{array}{cc}
\hline \text { Sample } & \text { 4-bit digital word } \\
\hline 1 & 0000 \\
2 & 0010 \\
3 & 0011 \\
4 & 0001 \\
5 & 0100 \\
6 & 0101 \\
7 & 0110 \\
8 & 1010 \\
9 & 1101 \\
10 & 1111 \\
11 & 1000 \\
12 & 0110 \\
13 & 0111 \\
14 & 1011 \\
15 & 1111 \\
\hline
\end{array}
$$