Suppose that in the U.S. in 2007, investment is $1,600 billion, saving is $1,400 billion, government expenditure on goods and services is $1,500 billion, exports are $2,000 billion, and imports are $2,500 billion.a. What is the amount of tax revenue?b. What is government budget balance?c. Is the government exerting a positive or negative impact on investment?d. What fiscal policy action might increase investment and speed economic growth?