If a product market takes $1,000 to enter the market, and has a 80% chance of producing being a good and a 20% chance of being a bad market, and good means the $1,000 will return $500 in addition to the $1,000 at the end, but bad means the $1,000 will lose $300 at the end, then the computation of the expected value is (again, remember to subtract the start up cost)