Question

What is the average rate of change for the sequence shown below? a coordinate plane showing the points negative 1, 4. 1, 3. 3, 2. 5, 1.

Answer 1

Answer: - 1/2 = - 0.5

Explanation:

1. Make the sequence clear. These are the given points (x,y):

• (-1, 4)
• (1, 3)
• (3, 2)
• (5, 1)

2. The average rate of change only takes into account the last and the first pairs of your intervals, those are (5, 1) and (-1, 4).

Average rate of change = [change in y] / [change in x] = [1 - 4] / [5 - (-1) ] =

  = - 3 / 6 = - 1/2 = - 0.5  ← answer

The averate ratre of change is the slope of the line that joins the first and last points. The fact that the result is negative means that there was a net decrease of the values.