When the allocation of resources in a free market environment is such that a different allocation would increase society's welfare, economists say:

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%.

Over the past decade, brands that were once available only to the wealthy have created more affordable product extensions, giving a far broader range of consumers a taste of the good life. jaguar, for instance, launched its x-type sedan, which starts at $30,000 and is meant for the "almost rich" consumer who aspires to live in luxury. by marketing to people who desire a luxurious lifestyle, jaguar is using:

In a perfectly competitive market, the long-run market supply curve tends to be horizontal or nearly so. what is another way to state this fact? (a) market supply is much more elastic in the long run than the short run. (b) in the long run, average total cost is minimized. (c) in the long run, price equals marginal cost. (d) market supply is much less elastic in the long run than the short run.