word problem help (derivative)

[spezialize]

Here is the word problem.. I don't even know where to begin..

The quanity (in lbs) of a gourmet ground coffee that is sold by a company at a price of p dollars per pound is Q=f(p). What is the meaning of the derivative f'(8)? What are the units? If f'(8) positive or negative?

 

[stapel]

What does f(p) measure? So f'(p) measures the change in what?

What are the units on Q? What are the units on p? So what would be the units on dQ/dp = f'(p)?

Without actual information on f(p), I don't see how you're supposed to guess the sign of f'(p) when the price-per-pound is eight dollars, though. Sorry.

Eliz.