Which of the following costs are most likely variable costs? Select all that apply. Group of answer choices

Screws used to fasten legs to a table

Monthly water bill for manufacturing plant

shipping costs on purchased materials

Monthly payment to security guard company, based on 1/12 of annual contract price.

The hawthorne works was a large western electric factory with 45,000 employees. during the 1920s and 1930s, hawthorne works was the site of some well-known industrial studies. in one of the studies, researchers investigated the impact of different working conditions on worker productivity. prior to the start of the study, researchers secretly measured workers' productivity for several weeks. then researchers chose two workers, who then chose their own teams. the teams were separated from the general workforce and completed their work in different experiment rooms where the researchers could observe them more easily. over a 5-year period researchers manipulated the structure of the workday for each team (number and duration of breaks and number of hours per shift). for each of these changes in working conditions, the researchers measured the effect on productivity. for some conditions, such as frequent short breaks, workers rebelled by intentionally decreasing productivity. why did the researchers secretly measure the workers' productivity before creating the two treatment groups? a, to create similar treatment groups so that a cause-and-effect relationship could be establishedb, to draw conclusions about the productivity of all workers in the plant based on the test groupsc, to directly control for confounding variablesd, to provide a baseline for measuring worker productivity

Aprice ceiling is “binding” if the price ceiling is set below the equilibrium price. suppose that the equilibrium price is $5. if a price ceiling is set at $6, this will not affect the market in any way since $5 remains a legally allowable price (since $5 < $6). a price ceiling of $6 is called a “non-binding” price ceiling. on the other hand, if the price ceiling is set at $4, the price ceiling is “binding” because the natural equilibrium price is $5 but that is no longer allowed. what happens when there is a binding price ceiling? at a price below the equilibrium price, quantity demanded exceeds quantity supplied. there is a shortage. normally, price increases eliminate shortages by increasing quantity supplied and decreasing quantity demanded. in this case, however, price increases are not allowed past the price ceiling. we therefore predict that the observed market price will be right at the price ceiling and there will be a permanent shortage. the observed quantity bought and sold will be dictated by the quantity supplied at the price ceiling. although consumers would like to buy more, there are no more units for sale

Awidower devised his fee simple interest in his residence as follows: “to my daughter for life, then to my oldest grandchild who survives her.” at the time of the widower’s death, he was survived by his only two children, a son and a daughter, and by one grandchild, his daughter’s son. a short time later, the daughter together with her son entered into a contract to sell the residence in fee simple to a buyer. the applicable jurisdiction continues to follow the common law rule against perpetuities, but has abrogated the rule in shelley’s case. at the closing, the buyer refused to purchase the residence. can the sellers compel the buyer to do so?