Respuesta :
					                   The answer would be B The average rate of change is $0.50, meaning that for every ten minutes of talk time, the bill increases by $0.50. 
					                
					                
					             For this case, the first thing we must do is find the average rate of change for the mentioned interval.
By definition we have to:
[tex] AVR = \frac{f(x2)-f(x1)}{x2-x1} [/tex]
Substituting values we have:
[tex] AVR = \frac{21.95-19.95}{40-0} [/tex]
Rewriting we have:
[tex] AVR = \frac{2}{40} [/tex]
 [tex] AVR = \frac{1}{20} 
AVR = 0.05 [/tex]
Answer:
C.) The average rate of change is $0.05, meaning that for each minute of talk time, the monthly bill increases by $0.05.
 
			                   
					                  