Probability
Free lessons and practice worksheets for probability — worked examples, common mistakes, and step-by-step solutions.
- 01Probability3 min read
Experimental Probability
Experimental probability measures the likelihood of an event based on actual experimental data rather than theoretical calculations. When a coin is flipped 50 times and lands heads 23 times, the experimental probability of heads equals 23/50 or 0.46. This approach appears in CCSS 7.SP standards where students conduct experiments and analyze the relationship between experimental and theoretical outcomes.
- 02Probability3 min read
Formal Probability Rules
Formal probability rules provide systematic methods for calculating the likelihood of combined events. The complement rule states that P(not A) = 1 - P(A), while the addition rule handles "or" scenarios and the multiplication rule manages "and" situations. These rules form the mathematical foundation for analyzing compound probability situations in statistics and data science.
- 03Probability3 min read
Introduction to Probability
Probability quantifies the likelihood of an event occurring, expressed as a number between 0 and 1, where 0 means impossible and 1 means certain. The basic formula divides favorable outcomes by total possible outcomes. For example, the probability of rolling a 4 on a standard die is 1/6, since there is 1 favorable outcome out of 6 total possibilities.
- 04Probability3 min read
Systematic Listing
Systematic listing is a method for identifying and organizing all possible outcomes of a probability experiment in a structured way. This technique uses tools like tables, tree diagrams, or ordered lists to ensure no outcomes are overlooked when determining sample spaces. The method appears prominently in CCSS 7.SP as students explore compound events and calculate probabilities from complete outcome sets.