(a) The ratio of Total Charges for Public Four-Year In-State from 2020-21 to 2021-22 is:
\[
\boxed{0.981:1.000}
\]
(b) The filled ratio table for 2021-22 is:
\[
\begin{array}{|c|c|c|}
\hline
\text{Private Room and Board} & \text{Public Four-Year Room and Board In-State} & \text{Public Two-Year Room and Board In-State} \\
\hline
13594 & 11881 & 9316 \\
\hline
1.1442 & 1 & 0.7841 \\
\hline
100 & 114.42 & 78.41 \\
\hline
\end{array}
\]