Question

The average cost of online photos decreased

from $0.50 per print to $0.13 per print between 2002 and
2013. Find the average rate of change in the cost. Explain
what it means.

Answer 1

The average rate of change is -0.034 which means that the decrease is -0.034 in the cost of per print per year

Explanation:

Given that

Price of print in 2002 = p1 =$0.50

Price of print in 2013 = p2 =$0.13

y1 = 2002

y2 = 2013

The rate of change is given by the formula:

`r = (decrease)/(run)`

Here decrease is the change in price and run is the difference in years.

Mathematically, it can be written as:

`r = (p_2-p_1)/(y_2-y_1)`

Putting the values

`r =(0.13-0.50)/(2013-2002)\\r = (-0.37)/(11)\\r =-0.0336\\r = -0.034`

Hence,

The average rate of change is -0.034 which means that the decrease is -0.034 in the cost of per print per year