Suppose variable 𝑥 is the speed of the car and variable 𝑦 is the car’s travel time to its destination. You suspect that if the car decreases its speed, its travel time to the destination increases. Does this follow a positive correlation, negative correlation, or no correlation?
Our 𝑥-axis represents the speed of the car, and our 𝑦-axis the time to destination. If the car decreases its speed, that will be moving from right to left on the graph. Then, the time to the destination increases. That’s moving up. And that means as we move left across the 𝑥-axis, we move up across the 𝑦-axis. This pink line is sloping downward.
It’s an image of a negative correlation. As our speed increases, the time decreases.