Bruce's hourly wage increased from $15.50 to $18.60. What rate of increase does this represent?

it went up from 15.50 to 18.60, so it really went up 3.10.

if we take 15.50 to be the 100%, what is 3.10 off of it in percentage?

[tex]\bf \begin{array}{ccll} amount&\%\\ \text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\ 15.50&100\\ 3.10&p \end{array}\implies \cfrac{15.50}{3.10}=\cfrac{100}{p}\implies p=\cfrac{3.10\cdot 100}{15.50}[/tex]