The cumulative average labor hours to assemble the first five units of product A was $15\mathrm{.}494$ hours. If the learning curve, based on the previous experience with similar products, is $90\%,$ what is the estimated time $($labor hours$)$ that will be required to assemble the ${22}^{th}$ unit?

The number of labor hours required to assemble the ${22}^{th}$ unit is $11\mathrm{.}2$ hours. $($Round to one decimal place.$)$