A rectangular hall has floor dimensions $30$ m by $10$ m and a height of$5$ m$.$ The total area of windows is $50$ m$\text{'}.$ The walls are plaster on brick, the ceiling is hardboard on battens and the floor is wood blocks on concrete. There are $200$ fabric seats. The reverberation time required for the hall, without audience, is $1\mathrm{.}5$ s at $500$ Ez$.$ Use table $11\mathrm{.}1$ to help calculate the area of thick pile carpet needed to achieve the correct reverberation time.