A time study technician has made a stop$-$watch time study for a process for $12$ times. The data is recorded as: $($Observation number, time in minutes$),(1,1\mathrm{.}56),(2,1\mathrm{.}61),(3,1\mathrm{.}59),(4,1\mathrm{.}51),(5,1\mathrm{.}48),(6,1\mathrm{.}49),(7,1\mathrm{.}60),(8.1\mathrm{.}55),(9,1\mathrm{.}57),(10,1\mathrm{.}48),(11,1\mathrm{.}58),(12,1\mathrm{.}50).$ What is the standard time if the rating for this operator is $90\%$ and $15\%$ allowance were added? $($Chapter $10)$

Group of answer choices

A$.1\mathrm{.}397$

B$.1\mathrm{.}497$

C$.1\mathrm{.}597$

D$.1\mathrm{.}697$

E$.$ None of them