the average cost of online photos decreases from 0.50 per print to $0.15 per print between 2002 and 2009. Find the average rate of change in the cost. Explain what it means
The average rate of changeis given by: m = (y2-y1) / (x2-x1) m = (0.50-0.15) / (2002-2009) Rewriting: m = (0.35) / (- 7) m = -0.05 $ / year Answer: the average rate of change in the cost is: m = -0.05 $ / year It means that the cost per print decreases 0.05 $ per year
