Abenefit of using a debit or credit card instead of cash is that it provides a paper record of a purchase. a proof of purchase is often needed in all of the following situations except:

The price of trade suppose that portugal and sweden both produce rye and wine. portugal's opportunity cost of producing a bottle of wine is 4 bushels of rye while sweden's opportunity cost of producing a bottle of wine is 10 bushels of rye. by comparing the opportunity cost of producing wine in the two countries, you can tell thatportugal/sweden has a comparative advantage in the production of wine.andportugal/sweden has a comparative advantage in the production of rye. suppose that portugal and sweden consider trading wine and rye with each other. portugal can gain from specialization and trade as long as it receives more rye for each bottle of wine it exports to sweden. similarly, sweden can gain from trade as long as it receives more bottles of wine for each bushel of rye it exports to portugal. based on your answer to the last question, which of the following prices of trade (that is, price of wine in terms of rye) would allow both sweden and portugal to gain from trade? a. 1 bushels of rye per bottle of wineb. 8 bushels of rye per bottle of winec. 9 bushels of rye per bottle of wined. 3 bushels of rye per bottle of wine

In its 2016 annual report, caterpillar inc. reported the following (in millions): 2016 2015 sales $38,537 $47,011 cost of goods sold 28,309 33,546 as a percentage of sales, did caterpillar's gross profit increase or decrease during 2016? select one: a. gross profit increased from 26.8% to 28.6% b. gross profit decreased from 28.6% to 26.5% c. gross profit increased from 71.4% to 73.2% d. gross profit decreased from 73.2% to 71.4% e. there is not enough information to answer the question.

Stocks a, b, and c are similar in some respects: each has an expected return of 10% and a standard deviation of 25%. stocks a and b have returns that are independent of one another; i.e., their correlation coefficient, r, equals zero. stocks a and c have returns that are negatively correlated with one another; i.e., r is less than 0. portfolio ab is a portfolio with half of its money invested in stock a and half in stock b. portfolio ac is a portfolio with half of its money invested in stock a and half invested in stock c. which of the following statements is correct? a. portfolio ab has a standard deviation that is greater than 25%.b. portfolio ac has an expected return that is less than 10%.c. portfolio ac has a standard deviation that is less than 25%.d. portfolio ab has a standard deviation that is equal to 25%.e. portfolio ac has an expected return that is greater than 25%.