Statistics & Probability
Every lesson explains the concept, works through examples, and gives you practice problems with full solutions. Work through them in order, or jump to the topic you need.
7 lessons
- Mean, Median and Mode: The Three AveragesHow to find the mean, median and mode of a data set, what each one measures, and how to choose between them when an outlier pulls the mean away from the middle.
- Dot Plots and Histograms: Showing the Shape of DataHow to read and build a dot plot and a histogram, why a histogram's bars touch, how bin width changes what you see, and what a statistical question is.
- Range, Interquartile Range and Mean Absolute DeviationHow to measure how spread out a data set is using range, interquartile range and mean absolute deviation, and why two sets with the same mean can be nothing alike.
- Box Plots: Reading the Five-Number SummaryHow to build a box plot from the five-number summary, what the box and whiskers each show, how to spot skew from the median line, and how to compare two groups.
- Probability: How Likely Is It?What probability means, how to calculate it for equally likely outcomes, why every probability sits between 0 and 1, and how experimental results differ from theory.
- Compound Probability: Two Events at OnceHow to find the probability of two events happening together using organised lists, tables and tree diagrams, and how dependent events differ from independent ones.
- Samples and Populations: Drawing Conclusions from DataWhy a random sample can represent a whole population, what makes a sample biased, how to estimate a population value from one, and how to compare two groups fairly.