What information does the payback period provide?

Suppose you are evaluating a project with the expected future cash inflows shown in the following table. Your boss has asked you to calculate the project's net present value $($NPV$).$ You don't know the project's initial cost, but you do know the project's regular, or conventional, payback period is $2\mathrm{.}50$ years.

$\backslash$table$[[$Year$,$Cash Flow$],[$Year $1,$$$375,000$