The standard bus fare in Chicago rose from $1.50 in 1995 to $2.25 in 2008. What was the percent increase?

1. Find the amount of increase: 2.25 minus 1.50 equals 0.75. 2. An increase is measured against the original amount, so divide: 0.75 divided by 1.50 equals 0.5. 3. Convert to percent form: the fare rose 50%. 4. Dividing by the new fare of 2.25 instead of the original gives 33%, the wrong-base trap. _Source: OpenStax Elementary Algebra (CC BY 4.0), Ch 3 "Math Models", section 3.2 Solve Percent Applications_