Word problem involving average rate of change

Answer:
(a): 190
(b): 750
Please see below for the steps.
Step-by-step explanation:
(a):
Use points (0,1000) and (3.1, 1589)
Use slope formula. The slope formula is also used to find average rate of change (just so you know).
y2-y1/x2-x1
1589-1000/3.1-0=589/3.1=190
Answer for (a) is 190
(b):
Use points (12.4, 4100) and (15.5, 6425)
Use slope formula.
y2-y1/x2-x1
6425-4100/15.5-12.4=2325/3.1=750
The answer for (b) is 750
Hope this helps!
Please mark as brainliest if correct!
Have a great day!