Identify the sequence graphed below and the average rate of change from n = 1 to n = 3. coordinate plane showing the point 2, 8, point 3, 4, point 4, 2, and point 5, 1. an = 8(one half)n − 2; average rate of change is −6 an = 10(one half)n − 2; average rate of change is 6 an = 8(one half)n − 2; average rate of change is 6 an = 10(one half)n − 2; average rate of change is −6