Option 1:The coral area will be protected (Gringoland Marine Park). This includes the construction costs of establishing the marine park, ongoing maintenance costs and costs due to foregone recreational fishing. The benefits are the increased tourism to visit the coral reef.

Option 2:Coral mining (Gringoland Coral Mining). This includes initial extraction costs and benefits from selling the coral for limestone. The ongoing cost are the impacts of coastal erosion.

For both options the set of costs and benefits is given for a 10-year period and discount rates of 3%, 6% and 9% are considered.

Q:In Option 1, a consultant revises the estimates of the benefits of tourism. It is estimated that this could be $250,000 per year with a probability of 0.3; $500,000 per year with a probability of 0.3; or $350,000 with a probability of 0.4. Calculate the expected benefits per year?

I need help learning how to calculate these new estimates