A $5-$person carpentry crew can frame the first model of a new subdivision house in $56$ hours. If their learning curve factor is $0\mathrm{.}94,$ it take them hours to frame the $15$ th house. The steady$-$state time is estimated to be $46\mathrm{.}5$ hours.

$45\mathrm{.}6$

$46\mathrm{.}5$

$44\mathrm{.}0$

$43\mathrm{.}97$