Interval Notation: $(-\infty, 4)$ Refer to the image below for the graph.
Work Step by Step
The solution set of the given inequality includes all the numbers that are less than $4$. The set includes all the numbers to the left of $4$ so $-\infty$ will be used on the left side of the interval notation. $4$ serves as a boundary though it is not part of the solution set. Thus, a parenthesis will be used on the right side of the interval. Thus, the interval notation equivalent of the given inequality is: $(-\infty, 4)$. To graph the solution set on a number line, plot a hole (or hollow dot) at $x=4$ then shade the region to its left. (refer to the attached image in the answer part above)