How does the U. S. economy benefit from either transaction (the foreign purchase of U. S. goods and services [exports] or the purchase of U. S. assets)?

One investigating company tracked all credit card purchase during 2012 and measured two variables: (1) the type of credit card used (visa, mastercard, american express, or discover), and (2) the amount (in dollars) of each purchase. identify the level of each variable measured.

Brian has been working for a few years now and has saved a substantial amount of money. he now wants to invest 50 percent of his savings in a bank account where it will be locked for three years and gain interest. which type of bank account should brian open? a. savings account b. money market account c. checking account d. certificate of deposit

Google started as one of many internet search engines, amazon started as an online book seller, and ebay began as a site where people could sell used personal items in auctions. these firms have grown to be so large and dominant that they are facing antitrust scrutiny from competition regulators in the us and elsewhere. did these online giants grow by fairly beating competition, or did they use unfair advantages? are there any clouds on the horizon for these firms -- could they face diseconomies of scale or diseconomies of scope as they continue to grow? if so, what factors may limit their continued growth?