Understand the difference between correlation (relationship between variables) and causation (one variable causing another). Learn about lurking variables.
Just because two variables move together (positive or negative correlation) does NOT mean one variable causes the change in the other.
Example: Ice cream sales and swimming pool drownings both increase in summer due to a 3rd confounding variable: high temperature.
Master percentage calculations with this comprehensive guide. Learn how to find percentages of numbers, calculate percentage changes, and solve real-world problems with step-by-step examples.
Learn what standard deviation means, why it matters, and exactly how to calculate it from scratch. Includes worked examples for both population and sample standard deviation.
A complete guide to the quadratic formula — what it is, where it comes from, how to use it, and how to interpret the discriminant. Includes multiple worked examples.