Does the temperature outside depend on the time of day, or does the time of day depend on the temperature outside? This may seem like a silly question, but to sketch a graph that represents this relationship, you first need to decide which axis will represent which quantity.

1. When you graph an equation such as $y=3x-5$, which variable ($x$ or $y$) depends on the other? Which is not dependent? (That is, which is independent?) Explain.

   Answer (a):

   The $x$ is independent and the $y$ is dependent because $y$ depends on $x$.

2. Which variable is dependent: temperature or time of day? Which variable is independent?

   Hint (b):

   Reread the questions in the opening paragraph of the problem.

   Answer (b):

   The time of day is independent and the temperature is dependent.

3. Sketch a graph (with appropriately named axes) that shows the relationship between temperature outside and time of day.

   Hint (c):

   Each day starts at midnight.

   Answer (c):