Assume that the total value of the following items is $600 billion in a specific year for Upper Mongoose: net exports = $50 billion; value of new goods and services produced in the underground economy = $75 billion; personal consumption expenditures = $300 billion; value of the services of stay-at-home parents = $25 billion; gross domestic investment = $100 billion; government purchases = $50 billion. What is Upper Mongoose’s GDP for the year? What is the size of the underground economy as a percentage of GDP? By what percentage would GDP be boosted if the value of the services of stay-at-home spouses were included in GDP?