$!$

Required information

For equipment that has a first cost $of$ $$13,000,$ the estimated operating costs and year$-$end salvage values are $as$ shown.

$\begin{array}{cc}\text{Y}\text{e}\text{a}\text{r}& \text{O}\text{p}\text{e}\text{r}\text{a}\text{t}\text{i}\text{n}\text{g}\text{C}\text{o}\text{s}\text{t}\text{\$}\\ \text{S}\text{a}\text{l}\text{v}\text{a}\text{g}\text{e}\text{V}\text{a}\text{l}\text{u}\text{e}\text{\$}& ?\\ 1& -1000\\ 7000& ?\\ 2& -1200\\ 5000& ?\\ 3& -1300\\ 4500& ?\\ 4& -2000\\ 3000& ?\\ 5& -3000\\ 2000& ?\end{array}$

Determine the economic service life ESL, $ati=10\%$ per year using factors.

The economic service life ESL, $is$ years with the $AW=$ $$-$