A university purchased two different paintings in one year. The value of Painting A over time is modeled by f left parenthesis x right parenthesis equals 50 comma 000 left parenthesis 1.064 right parenthesis Superscript x. The value of Painting B is represented by the graph at the right. Find the average rate of change of the value of each artwork over a 4-year time period. Which art work's value is increasing more quickly?
painting a= per year
painting b=per year