$11\mathrm{.}6($Calculating IRR$)($Related to Checkpoint $11\mathrm{.}1$ on page $367)$ What are the IRRs for the following projects?

$1.$ An initial outlay of $5,000$ resulting in a single cash inflow of $9,962$ in $8$ years.

$2.$ An initial outlay of $5,000$ resulting in a single cash inflow of $12,968$ in $10$ years.

$3.$ An initial outlay of $5,000$ resulting in a single cash inflow of $48,231$ in $20$ years.

$4.$ An initial outlay of $5,000$ resulting in a single cash inflow of $5,995$ in $3$ years

not in excel simple formula.