Answer and Explanation:
1. Describe the relationship shown in the graph.
The graph shows that as the temperature outside gets hotter, the heating cost gets lower.
This makes sense because when it is 90°F outside, there's no need to heat inside; at that point most people would want air conditioning to cool down the room.
2. Draw the best-fit line.
See the attached image.
The best-fit line goes through the average of the data points.
3. Does the scatter plot show a positive, negative, or no relationship?
The scatter plot shows a negative relationship because as the graph advances horizontally, it decreases vertically.