Statistics & Probability
Overview
Averages, distributions, uncertainty, and data analysis.
Lessons
Understanding Data and Types of Data
Learn how to classify data correctly before analyzing it — the foundation of every statistical decision.
Organizing Data with Frequency Tables
Turn raw data into structured frequency tables that reveal patterns, proportions, and trends at a glance.
Calculating the Mean (Average)
Master the arithmetic mean and weighted mean — the most widely used summary statistics in business, science, and everyday life.
Median and Mode: Finding the True Center
Learn when the middle value or most frequent value gives a truer picture of data than the mean — and how to find both.
Measuring Spread: Range, Variance, and Standard Deviation
Go beyond the average — learn to quantify how consistent or volatile your data is using range, IQR, variance, and standard deviation.
Introduction to Probability
Learn how to express and calculate the likelihood of any event as a number between 0 and 1 — the foundation of all statistical reasoning.
Calculating Probability: Single Events
Apply probability rules to real problems — compute probabilities for single events using addition rules, mutually exclusive events, and known sample spaces.
Independent vs. Dependent Events
Understand how the probability of one event changes — or doesn't — based on whether another event already occurred.
Counting Methods: Permutations and Combinations
Learn when order matters and when it doesn't — and use factorials, permutations, and combinations to count large possibility spaces precisely.
Interpreting Data and Making Decisions
Pull everything together — use Z-scores, percentiles, and correlation to read data critically, evaluate claims, and make evidence-based decisions.