Answer: 20 
Step-by-step explanation:
 
        
             
        
        
        
Here, to find the average rate of change, you would simply divide 270 by 63. And when that is done, you would get a long decimal. 4.285714285714286
And since you obviously can't put in such a long decimal as your answer, you would round it instead. Once rounded, you would end up with 4.29 (because the number after 8 is five, which rounds up, which would turn the 8 to 9.)
        
             
        
        
        
Simply divide with your calculator
18049/14 ≈ 1289.214
 ≈ 1289.214