Let's begin by identifying key information given to us:
Bill (b) = $234.50,
Tip (t) = 20% of the bill
The tip is calculated as shown below:
[tex]\begin{gathered} Tip=20\text{\% x }Bill \\ Tip=20\text{\% x }234.50=0.2\cdot234.50=46.90 \\ Tip=\text{\$}46.90 \end{gathered}[/tex]Therefore, the tip is $46.90