Dana, who is a trained yoga instructor, spends 4 hours on Monday baking and packing 10 boxes of cookies. She sells the cookies for $10 a box. Given that she can also teach yoga for $80 an hour, what is her opportunity cost of baking cookies?A. $220B. $800C. $320D. $420E. $100

Afreelance​ singer-songwriter is planning the restoration of a recently purchased civil​ war-era farmhouse. while he professes an enjoyment​ of, and talent in the construction​ trades, the theory of comparative advantage implies that a. the value of what he imports​ (in this​ case, professional contractor​ services) must equal the value of what he exports​ (songs). b. he should concentrate on the restoration work since his​ out-of-pocket costs will be much lower than if he hires professionals. c. ​self-sufficiency is​ advantageous, hence he should split his time between music and construction. d. the income lost while away from music will likely exceed the savings realized by doing the work​ himself, thus, he should hire professionals to do the restoration work. e. he ought to do as much of the work himself as possible since imports​ (in this​ case, professional contractor​ services) should always be restricted to those things that cannot be done internall

Employees at a library check out books to patrons. books have an isbn and a name. the library sometimes has multiple copies of the same book. books have one or more authors. a patron is an individual who has an active (non-expired) library card. for each library card, we store the person's first and last names and their address. for each employee, we store their employee id, current salary, first and last name and their address. we also store the employee id of their current manager. each time we check out a book to a patron we need to store the date of the transaction, the employee who checked out the book to the patron, and the library card of the patron. some employees have library cards. if an employee patron turns in a book late, the fine that they pay is a percentage of their salary. some employees are authors who have library cards—they are allowed to check out as many books as they like.

Consider a treasury bill with a rate of return of 5% and the following risky securities: security a: e(r) = .15; variance = .0400 security b: e(r) = .10; variance = .0225 security c: e(r) = .12; variance = .1000 security d: e(r) = .13; variance = .0625 the investor must develop a complete portfolio by combining the risk-free asset with one of the securities mentioned above. the security the investor should choose as part of her complete portfolio to achieve the best cal would be a. security a b. security b c. security c d. security d