the data below are for a private (no government) closed economy. all figures are in billions of dollars. refer to the table above. if planned investment is $18 billion, then at the $660 billion level of disposable income, there will be an: group of answer choices unplanned increase in inventories of $12 billion unplanned decrease in inventories of $30 billion unplanned decrease in inventories of $12 billion unplanned increase in inventories of $30 billion