Answer:
The items arranged from least steep to steepest rate of change are:
Michele's spending: $125 to $75 over time, spending $10 per week.
Elisa's puppy's weight: Started at 4 pounds, gained 5 pounds per month until it was 9 months old.
f(t): -6.2x + 2.9, a linear function with a rate of change of -6.2.
g(x): 8.1x + 45.64, a linear function with a rate of change of 8.1.
So the correct order is:
Michele's spending
Elisa's puppy's weight
f(t)
g(x)
Explanation: