Our inequation is

It means we will graph every point that satisfies the inequation, we can read it as values at the axis that satisfies "b" less than 4. Some examples that satisfy it
3 is less than 4, then it must be in the graph
1 is less than 4, then it must be in the graph
-1 as well
-3 too, -6, -100, -2000 and so on.
But see it's only less than, equal to 4 is not included in the solution, we represent it as
It means that our graph will be like
We will put the empty circle at 4 and paint all on the left side.