The bank forecasts the following one$-$year interest rates one and two years in the future: $3\mathrm{.}80\%$ and $4\mathrm{.}20\%.$ The current three$-$year interest rate is $4\mathrm{.}20\%.$ Estimate the current one$-$year interest rate.

$4\mathrm{.}4\%.$

$4\mathrm{.}8\%$

None of the listed answers.

$4\mathrm{.}6\%.$