One measure of the extent of competition in an industry is the concentration ratio. what level of concentration indicates that an industry is an oligopoly? most economists believe that a four-firm concentration ratio of ▼ greater less than nothing percent indicates that an industry is an oligopoly. (enter your response as an integer.)

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?

Wren pork company uses the value basis of allocating joint costs in its production of pork products. relevant information for the current period follows: product pounds price/lb. loin chops 3,000 $ 5.00 ground 10,000 2.00 ribs 4,000 4.75 bacon 6,000 3.50 the total joint cost for the current period was $43,000. how much of this cost should wren pork allocate to loin chops?

Areal estate agent is considering changing her cell phone plan. there are three plans to choose from, all of which involve a monthly service charge of $20. plan a has a cost of $.42 a minute for daytime calls and $.17 a minute for evening calls. plan b has a charge of $.52 a minute for daytime calls and $.15 a minute for evening calls. plan c has a flat rate of $80 with 275 minutes of calls allowed per month and a charge of $.38 per minute beyond that, day or evening.a. determine the total charge under each plan for this case: 150 minutes of day calls and 70 minutes of evening calls in a month. (do not round intermediate calculations. round your answer to 2 decimal places. omit the "$" sign in your response.)c. if the agent will use the service for daytime calls, over what range of call minutes will each plan be optimal? (round each answer to the nearest whole number.include the indifference point itself in each answer.)d. suppose that the agent expects both daytime and evening calls. at what point (i.e., percentage of total call minutes used for daytime calls) would she be indifferent between plans a and b?