Sheila's salary fell from $42,000 last year to $37,800 this year because of furlough days. Find the percent decrease.

1. Find the amount of decrease: 42,000 minus 37,800 equals 4,200. 2. A decrease is measured against the original amount, so divide 4,200 by 42,000. 3. That quotient is 0.10. 4. Convert to percent form: her salary decreased 10%. 5. In units: 4,200 dollars out of every 42,000 dollars is 10 dollars per 100 dollars. 6. Dividing by the new salary of 37,800 gives about 11%, the wrong-base trap. _Source: OpenStax Elementary Algebra (CC BY 4.0), Ch 3 "Math Models", section 3.2 Solve Percent Applications_