The problem statement suggests you want a linear function like the one shown in the attachment.
A real taxi might charge you for a whole mile, even though you rode only a partial mile. The problem statement does not describe the charges as being like that.
The title of the graph might be "Stevens Taxi Service Charges."
The cost for a 5-mile ride will be $5.00 +$2.50*5 = $17.50.
