From the table we can see: Number of songs: Cost: 0 $ 0 1 $1.25 2 $2.50 3 $3.75 4 $5.00 Therefore the rate of change is: (2.50 - 1.25) / ( 2 - 1 ) = $1.25 Answer: It means that : C. The cost increases $1.25 for each additional song that is downloaded.
