After stinging its victim, the honeybee leaves behind the barbed stinger, poison sac and muscles that continue to pump venom into the wound. visscher et al. (1996) compared the effects of two methods of removing the stinger left behind: scraping off with a credit card or pinching off with thumb and index finger. a total of 40 stings were induced on volunteers. twenty were removed with the credit card method and 20 were removed with the pinching method. the size of the subsequent welt by each measurement came from two volunteers (both authors of the study), each of whom received one treatment 10 times on the one arm and the other treatment 10 times on the other arm. pinching led to a slightly smaller average welt, but the difference between the methods was not significant. does this study include a control group? enter the number of the best answer choice from the options below

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.

With signals from no-claim bonuses and deductibles, a. the marginal cost curve for careful drivers lies to the left of the marginal cost curve for aggressive drivers b. auto insurance companies insure more aggressive drivers than careful drivers because aggressive drivers have a greater need for the insurance c. the market for car insurance has a separating equilibrium, and the market is efficient d. most drivers pay higher premiums than if the market had no signals

Your sister is thinking about starting a new business. the company would require $375,000 of assets, and it would be financed entirely with common stock. she will go forward only if she thinks the firm can provide a 13.5% return on the invested capital, which means that the firm must have an roe of 13.5%. how much net income must be expected to warrant starting the business? a. $41,234b. $43,405c. $45,689d. $48,094e. $50,625