The Rialto Theatre purchased a new projector costing $$82,000$ on January $1,2019.$ Because of changing technologies, the projector is estimated to last four years after which it will be obsolete and have a salvage value of $$4,000$ as a collectors$$ item.

Compute the depreciation expense for $2019$ using the straight$-$line method.

Compute the net book value at the end of $2019.$