Bill Gates is the world's second richest person whose net worth is estimated at $54 billion. The idea that Bill Gates marginal utility for his 54 billionth dollar is less than someone else's 1000th dollar is the

The balance of payments is in equilibrium when

A) the sum of the current account balance and capital account balance is zero. B) net exports are zero. C) net foreign investment is zero. D) real foreign investment is equal to net exports.

Professor's economics students are constructing models for how gasoline prices change. Maria's model has very realistic assumptions and is quite complex. Anna's model is less complicated and less realistic. Maria's model correctly predicts gas price

increases 5% of the time. Anna's model predicts correctly 15% of the time. On the basis of usefulness or "goodness," Professor will give which student's model the higher grade and why? A) Maria's model gets the higher grade because it is more complex. B) Anna's model gets the higher grade because it is simpler. C) Maria's model gets the higher grade because it is more realistic. D) Anna's model gets the higher grade because it predicts accurately more often.