The table is for the function $f(x) = 3x$. To complete the table:

1. When $x = 0$:
   $f(x) = 3 \times 0 = 0$

2. When $x = 1$:
   $f(x) = 3 \times 1 = 3$

3. When $x = 2$:
   $f(x) = 3 \times 2 = 6$

4. When $x = 3$:
   $f(x) = 3 \times 3 = 9$

So the completed table is:

Let me know if you have questions or would like further assistance!

Related Questions:

1. What would $f(x)$ equal if $x = -1$?
2. How can we describe the graph of $f(x) = 3x$?
3. What is the slope of the linear function $f(x) = 3x$?
4. If $f(x) = 12$, what is $x$?
5. How does the function $f(x) = 3x$ change if the coefficient is altered?

Tip: For linear functions $f(x) = mx$, $m$ represents the slope, which determines how steep the line is.