Answer:
Monthly service fee is like the fixed cost which is basically the y-value where graph crosses the y-axis.
From graph we see that graph crosses at 1 on y-axis so monthly service fee according to sample graph = $1
Now the per check fee works like slope of the line.
To find the slope we need two points so find any two points on the graph of line. I'm using points (1,0) and (4,3)
now slope can be found using formula
Hence per check fee will be $0.5 as per attached sample graph.
You can use same technique for the original graph given with this question.
Explanation: