411 REFERENCE · Wikibooks
Basic Algebra/Proportions and Proportional Reasoning/Chapter Review
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
Lesson 1. Proportions
Lesson 2. Percents
Lesson 3. Percent of Change
Lesson 4. Weighted Averages
Lesson 5. Direct and Inverse Variation
Lesson 6. Solving Similar Triangles using Proportions