13. She will have saved 1020 in 12 months and 467.5 in 11. 14. In 1 month she'll have saved 42.5 in 1 month and 212.5 in 5 months. 15. in 3 months she'll save 125 and 190 in 4 months. 16. The rate of change is 42.5. 17. It depends on your thoughts on what was more challenging, and knowing the rate of change can tell you half of certain amounts of money earned or what the difference between her earning months are. 18. I have no idea the y intercept someone else might be able to help you with that though. 19. I don't know that either someone else might help better.
You can round 976 to 1000 and 522 to 500. So it would be 1000 - 500 = 500. The answer you would get after subtracting 976-522 would be more than 400 if you round it.
