#### Answer

$\text{Set Builder Notation: }
\left\{ x|x\lt7 \right\}
\\\text{Interval Notation: }
\left( -\infty,7 \right)$

#### Work Step by Step

$\bf{\text{Solution Outline:}}$
Use the properties of inequality to solve the given inequality, $
4x\lt28
.$ Write the answer in both set-builder notation and interval notation. Finally, graph the solution set.
In the graph, a hollowed dot is used for $\lt$ or $\gt.$ A solid dot is used for $\le$ or $\ge.$
$\bf{\text{Solution Details:}}$
Using the properties of inequality, the given is equivalent to
\begin{array}{l}\require{cancel}
4x\lt28
\\\\
x\lt\dfrac{28}{4}
\\\\
x\lt7
.\end{array}
Hence, the solution set is
\begin{array}{l}\require{cancel}
\text{Set Builder Notation: }
\left\{ x|x\lt7 \right\}
\\\text{Interval Notation: }
\left( -\infty,7 \right)
.\end{array}