The Following Table Contains Data from the Historic Flood of the Cedar

The following table contains data from the historic flood of the Cedar River at Cedar Rapids, Iowa during June 2008. Readings were taken at 6:00 A.M. each day. $\begin{array} { | c | c | } \hline \text { Day } & \text { Stage (ft) } \\\hline 08 & 10.46 \\\hline 09 & 13.79 \\\hline 10 & 17.54 \\\hline 11 & 19.62 \\\hline 12 & 25.88 \\\hline 13 & 31.03 \\\hline 14 & 29.23 \\\hline 15 & 24.93 \\\hline 16 & 21.95 \\\hline 17 & 20.13 \\\hline 18 & 18.85 \\\hline 19 & 16.25 \\\hline 20 & 13.63 \\\hline 21 & 12.12 \\\hline 22 & 10.94 \\\hline\end{array}$
Source: US Army Corps of Engineers - Rock Island District - Water Control Center
(a) Find the average daily rate of change of the river level over each of the following periods:
(i) [08, 13]
(ii) [13, 22]
(iii) [12, 13]
(iv) [13, 14]
(b) Estimate the daily rate of change of the stage level on June 14th.