Smithson Mining operates a silver mine in Nevada. Acquisition, exploration, and development costs totaled $$5\mathrm{.}8$ million. After the silver is extracted in approximately five years, Smithson is obligated to restore the land to its original condition, including constructing a wildlife preserve. The company's controller has provided the following three cash flow possibilities for the restoration costs: $(1)$ $$520,000,20\%$ probability; $(2)$ $$570,000,35\%$ probability; and $(3)$ $$670,000,45\%$ probability. The company's credit$-$adjusted, risk$-$free rate. of interest is $6\%.$