Answer:
The rate of change of Paolo Portraits is $15 per photo and the rate of change of clear image studio is $12 per photo. Paolo Portraits charges are higher than the clear image studio.
Step-by-step explanation:
The rate of change represent the change in one variable with respect to another variable. It also known as slope.
It is given that Paolo Portraits charges $15 per photo with no sitting fee. It means the rate of change of Paolo Portraits is $15 per photo.
The function for Paolo Portraits charges is defined as

From the given graph it is noticed that the line is passing through the points (0,0) and (1,12).
The slope of the line is

The function for clear image studio is

It means the rate of change of clear image studio is $12 per photo.
The rate of change of Paolo Portraits is more than rate of change of clear image studio.
Therefore Paolo Portraits charges are higher than the clear image studio.