Basic College Mathematics (10th Edition)

$375\%$
We convert the fraction ($3\frac{3}{4}$) to a percent: $\displaystyle 3\frac{3}{4}=\frac{x}{100}$ $\displaystyle \frac{15}{4}=\frac{x}{100}$ Cross-multiply: $15*100=4x$ $1500=4x$ $x=1500/4=375\%$