Companies invest in expansion projects with the expectation of increasing the earnings of its business.

Consider the case of Fox Co$.$:

Fox Co$.$ is considering an investment that will have the following sales, variable costs, and fixed operating costs:

$\backslash$table$[[,$Year $1,$Year $2,$Year $3,$Year $4],[$Unit sales,$3,500,4,000,4,200,4,250],[$Sales price,$$38\mathrm{.}50,$$$39\mathrm{.}88,$$$40\mathrm{.}15,$$$41\mathrm{.}55$