Answer
Refer to the graph below.
Work Step by Step
The graph of an equation of the form $y=k$ is a horizontal line whose y-intercept is $0, k)$.
Each point on the line has a y-coordinate of $k$.
Thus, the graph of $y=4$ is a vertical line whose y-intercept is $(0, 4)$.
Each point on the line has a y-coordinate of $4$.
This, means that the following points are all on the line:
$(-2, 4)$, $(0, 4)$, and $(2, 4)$
Plot the three points listed above then connect them using a line to complete the
graph. (refer to the attached image in the answer part above for the graph)