Please explain to me how to get to the correct answer given the CFs provided $($without using excel, I need a formula$),$ I am very lost. Thank you!

$8\mathrm{.}3$ Using the Total Loan Cash Flows from the table above, what is the all$-$in$-$cost $($i$.$e$.,$ the internal rate of

return$)$ of the loan including the SOFR rate, fixed spread and upfront fee? $($Round percentage answer to two

decimal places. Note: I will assume your Total Loan Cash Flows from the prior answer are correct in scoring

this question.$)$