SOLUTION: can you please help with this question? The average cost of online photos went from $0.50 per print to $0.15 per print between 2002 and 2009. What is the rate of change?

Algebra ->  Linear-equations -> SOLUTION: can you please help with this question? The average cost of online photos went from $0.50 per print to $0.15 per print between 2002 and 2009. What is the rate of change?      Log On


   

Question 1204086: can you please help with this question? The average cost of online photos went from $0.50 per print to $0.15 per print between 2002 and 2009. What is the rate of change?
Answer by ikleyn(52908) About Me  (Show Source):
You can put this solution on YOUR website!
.

In this problem, the rate of change is  

    rate of change = %280.15+-+0.50%29%2F%282009-2002%29 = -0.35%2F7 = -o.05  dollars per year.


Here the rate of change is NEGATIVE, reflecting the fact that the cost is decreasing.


To calculate, we take the difference "the future price MINUS the current price"
(the order is IMPORTANT).


Then we divide this difference by the time period duration (7 years in this problem).


The final value has the dimension "dollars per year".

Solved, with complete explanations.