The table shows increases (+) and decreases (-) in the lake level for the given period. By doing a cummulative addition, it would be easy to tell what the level was eventually.
We shall take the initial level of water to be x feet. The cummulative addition is now shown below;
Initial level + changes in subsequent levels
[tex]\begin{gathered} \text{Changes}=x+0.5-1.26+0.32+3.71-1.27-1.0 \\ \text{Changes}=x \\ \text{Changes}=x+1 \end{gathered}[/tex]
