Answer
$[0,4]$
Refer to the graph below.
Work Step by Step
Since both the left and right boundaries of the given inequality involve "less than or equal to", then the interval notion will have bracket on both ends.
Hence, the given inequality can be written as $[0,4]$.
To graph, plot solid dots at $x=0$ and $x=4$, then shade the region between them.
See the figure below.
