Answer:
I believe it is 8
Step-by-step explanation:
Edit: It said the average rate of change over the interval AC.
1. So I just added 2+6+18=26
2. Next to get the average interval you have to divide by how many numbers there were in the equation which is THREE
3. So 26/3 is 8.66 repeating but if you round up to whole number it would be 8.