Answer:
Second from top...
The average rate of change is $0.07, meaning that for each minute of talk time, the monthly bill increases by $0.07.
Step-by-step explanation:
Pick any two points and calculate the slope which will represent the rate of change:
(Minutes, Cost)
(0, 9.95)
(10, 10.65)
Rate of change:
slope m = (y₂ - y₁) / (x₂ - x₁)
= (10.65 - 9.95) / (10 - 0)
= 0.7 / 10
= 0.07
y is cost
m is rate of change
x is minute(s) use
b is fixed monthly cost regardless if any minutes is used
y = mx + b
y = .07x + 9.95
