Identify the sequence graphed below and the average rate of change from n = 1 to n = 3. coordinate plane showing the point 1, 8, point 2, 4, point 4, 1, and point 5, .5 an = 8(one half)n − 1; average rate of change is −3 an = 10(one half)n − 1; average rate of change is 3 an = 8(one half)n − 1; average rate of change is 3 an = 10(one half)n − 1; average rate of change is −3