E Ecosystems- Healthy ecosystems are essential for the survival and success of countless species on Earth. Scientists are studying the dynamics of these natural systems to assess the benefits of protecting existing ecosystems or restoring those that have been disrupted by human activities or invasive species. What else can be done to preserve these delicate, critical ecosystems?

In 2007, americans smoked 19.2 billion packs of cigarettes. they paid an average retail price of $4.50 per pack. a. given that the elasticity of supply is 0.50.5 and the elasticity of demand is negative 0.4−0.4, derive linear demand and supply curves for cigarettes. the demand equation is qdequals=nothingplus+nothing times ×p and the supply equation is qsequals=nothingplus+nothing times ×p.

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?

Winston churchill's stamp collection was valued at $14 million when he died. at auction, it brought in only $4 million. what was it worth? why?