#### Answer

There was a $14.20\%$ decrease in Bill's hourly wage.

#### Work Step by Step

First, find the decrease in hourly wage:
$=\$25.50-\$21.88
\\=\$3.62$
RECALL:
$\text{percent decrease}=\dfrac{\text{decrease in value}}{\text{original value}}$
The given problem has:
original value =$\$25.50$
decrease in value = $\$3.62$
Solve for the percent decrease using the formula above to obtain:
percent decrease
$= \dfrac{3.62}{25.50}
\\=0.1419607843
\\=0.1419607843 \times 100\%
\\=14.19607843\%
\\\approx 14.20\%$
Thus, there was a $14.20\%$ decrease in Bill's hourly wages.