First post here.
So, to further explain my question, I want to know what to look for when trying to determine what value changes with respect to the other value; basically which value is $x$, and which is $y$?
Here's a following table to help illustrate:
| Time | 06:00 | 10:00 | 14:00 | 18:00 |
|---|---|---|---|---|
| Temperature | +4°C | -2°C | +4°C | -2°C |
Question here is: Find the change ratio between 14:00 and 18:00. Is time here the $x$-value or is it the temperature? And how do we find out?