On August $1,2022,$ Colombo Company$$s treasurer signed a note promising to pay $$122,100$ on December $31,2022.$ The proceeds of the note were $$115,800.$

Required:

a$.$ Calculate the discount rate used by the lender.

Note: Enter your answer as a percentage rounded to $1$ decimal place $($i$.$e$.,32\mathrm{.}1).$