Can someone please check my work? I'm not sure if it's correct but when I worked out the problem.

The question was: A cell phone plan has a monthly cost that is shown in the table below. What is the correct statement regarding the average rate of change during the 40-minute time of talk?
(I'll show the graph)

Question

Can someone please check my work? I'm not sure if it's correct but when I worked out the problem.
 
The question was:  A cell phone plan has a monthly cost that is shown in the table below. What is the correct statement regarding the average rate of change during the 40-minute time of talk?
(I'll show the graph)

kdr1308 · Answer

attachment

kdr1308 · Answer

The average rate of change is $1.00, meaning that for each minute of talk time, the monthly bill increases by $0.10.

fortytherapper · Answer

Your answer is a simplified answer, but I like it!