Q$3(6$ pts$)$: The bottom line for the management is every store should at least achieve break$-$even, meaning one dollar input cost generates at least one dollar revenue $($i$.$e$.,$ a multifactor productivity of at least $1).$ If this bottom line was not met last month, the management plans to negotiate the rent for floor area with the landlord of these $5$ stores to sign a longer term lease because their lease expires very soon.

Assuming sale revenues and labor, inventory, and overhead costs for the near future will remain about the same as last month, calculate the threshold $($precise to the first decimal place$)$ of the monthly rent per square foot for floor area for meeting the above bottom line. That is$,$ as long as the floor rent is negotiated and lowered to this threshold rent, the above bottom line just starts to be met. If all stores met the above bottom line last month already, no calculation is needed and just answer $"$N$/$A$"$ below.