Mikkelson Corporation's stock had a required return of $13\mathrm{.}75\%$ last year, when the risk$-$free rate was $3\%$ and the market risk premium was $4\mathrm{.}75\%.$ Then an increase in investor risk aversion caused the market risk premium to rise by $2\%.$ The risk$-$free rate and the firm's beta remain unchanged. What is the company's new required rate of return? $($Hint: First calculate the beta, then find the required return.$)$ Do not round your intermediate calculations.

$14\mathrm{.}07\%$

$14\mathrm{.}80\%$

$21\mathrm{.}38\%$

$18\mathrm{.}64\%$

$18\mathrm{.}28\%$