We can use the first and the last point of the table to find the average rate of change during the 40-minute talk time.
At t=0, the charges are $ 9.95
at t=40, the charges are $12.75
Average rate of change from t=0 to t=40 can be calculated as:
This means, the average rate of change is $0.07, meaning that for each minute of talk time, the monthly bill increases by $0.07. (Option B)
At t=0, the charges are $ 9.95
at t=40, the charges are $12.75
Average rate of change from t=0 to t=40 can be calculated as:
This means, the average rate of change is $0.07, meaning that for each minute of talk time, the monthly bill increases by $0.07. (Option B)