A new machine shop $(\backslash$alpha ave $=0\mathrm{.}21)$ will have a control room $(\backslash$alpha ave $=0\mathrm{.}07)$ which will provide a

quieter environment for the operators, as pictured below. Both rooms have $18$ foot ceiling. A

wall will be constructed between the control room and the machine area from materials that

has a transmission loss of $68$ dB and for access the will use a $6$ ft by $6$ ft door $($TL $=25$ dB$)$

with a $(1)/(2)$ inch gap at the bottom. The operators also plan to install a double paned glass

veiweing window in the wall $($TL $=22$ dB$).$ IF the minimum required transmission loss

between the two rooms is $30$ dB$,$ what is the largest window that can be installed $($ft$2).$ Note:

all transmission loss values are given at $1000$ Hz$.$