The number of cell phone subscribers in a country in the years 2000-2005 was projected to follow the equation n(t) = 39t + 64 million subscribers in year t (t = 0 represents january 2000). the average annual revenue per cell phone user was $350 in 2000. if we assume that due to competition the revenue per cell phone user decreases continuously at an annual rate of 20%, we can model the annual revenue as r(t) = 350(39t + 72)e^0.2t million dollars.

(a) determine when to the nearest 0.1 year the revenue was projected to peak.

b) determine the revenue, to the nearest $1 million, at that time.

Captain john's yachts, inc., located in fort lauderdale, florida, rents three types of ocean-going boats: sailboats, cabin cruisers, and captain john's favorite, the luxury yachts. captain john advertises his boats with his famous "you rent"we pilot" slogan, which means that the company supplies the captain and crew for each rented boat. each rented boat has one captain, of course, but the crew sizes (deck hands, galley hands, etc.) differ. the crew requirements, in addition to a captain, are one for sailboats, two for cabin cruisers, and three for yachts. ten employees are captains, and an additional 18 employees fill the various crew positions. currently, captain john has rental requests for all his boats: four sailboats, eight cabin cruisers, and three luxury yachts. if captain john's daily profit contribution is $50 for sailboats, $70 for cruisers, and $100 for luxury yachts, how many boats of each type should he rent?

Consider how health insurance affects the quantity of health care services performed. suppose that the typical medical procedure has a cost of $160, yet a person with health insurance pays only $40 out of pocket. her insurance company pays the remaining $120. (the insurance company recoups the $120 through premiums, but the premium a person pays does not depend on how many procedures that person chooses to undergo.) consider the following demand curve in the market for medical care. use the black point (plus symbol) to indicate the quantity of procedures demanded if each procedure has a price of $160. then use the grey point (star symbol) to indicate the quantity of procedures demanded if each procedure has a price of $40. q d at p=$160 q d at p=$40 0 10 20 30 40 50 60 70 80 90 100 200 180 160 140 120 100 80 60 40 20 0 price of medical procedures quantity of medical procedures demand if the cost of each procedure to society is truly $160, the quantity that maximizes total surplus is procedures. economists often blame the health insurance system for excessive use of medical care. given your analysis, the use of care might be viewed as excessive because consumers get procedures whose value is than the cost of producing them.

Zeta corporation is a manufacturer of sports caps, which require soft fabric. the standards for each cap allow 2.00 yards of soft fabric, at a cost of $2.00 per yard. during the month of january, the company purchased 25,000 yards of soft fabric at $2.10 per yard, to produce 12,000 caps. what is zeta corporation's materials price variance for the month of january?