I can't exactly graph it for you but I can tell you how it looks like :-) So, your graph would have a positive slope that is 4/3. The y-intercept is below the x-axis at -1/3. From that point, the next point to the right would be (3, 11/3). Basically it would go up 4 and right 3 from your y-intercept. I hope this helps :-)
You want to multiply 87.60 and 25.60 by 10. 87.60x10=876. 25.60x10=256.876-256=620. Then you will take 1/4 of 620 to get the answer 155 is what she paid for lessons.