AP Stats Probability Practice Quiz
Sharpen your skills with focused practice questions
Study Outcomes
- Understand fundamental probability concepts and terminology.
- Analyze random experiments to identify outcomes and compute probabilities.
- Apply theoretical probability models to solve real-world problems.
- Evaluate the impact of independent and dependent events on probability calculations.
- Synthesize key AP Statistics concepts to enhance problem-solving strategies.
AP Stats Probability Cheat Sheet
- Addition Rule - Think of this as combining event buckets. For events that can't happen together (mutually exclusive), simply add their probabilities. If they can overlap, subtract the intersection so you don't double‑count shared outcomes. Fiveable's Probability Rules
- Multiplication Rule - This rule is all about joint occurrences. For independent events, multiply their probabilities directly. When events are dependent, factor in conditional probability by using P(A) × P(B|A) to capture the updated chance. Fiveable's Probability Rules
- Conditional Probability - Here you're zooming in on the chance of A given that B already happened. Calculate it by dividing the probability of both A and B occurring by the probability of B. This lets you update your expectations based on new information. Fiveable's Probability Rules
- Bayes' Theorem - Bayes lets you flip probabilities when you get fresh evidence. Use P(A|B) = [P(B|A) × P(A)] / P(B) to revise your belief in A after observing B. It's a powerful tool for real‑world decision making and diagnostics. Fiveable's Probability Rules
- Complementary Events - Sometimes it's easier to calculate what won't happen. The probability of the complement (A′) is just 1 minus the probability of A. This trick simplifies problems like "at least one" or "none of the above." Fiveable's Probability Rules
- Expected Value - Think of this as the long‑run average outcome. Multiply each possible value by its probability and sum them up to get E(X). It tells you what to expect on average if you repeat the experiment many times. Statistics How To: AP Formulas
- Variance of a Random Variable - Variance measures how spread out your outcomes are. Calculate Σ[(xᵢ − μ)² × P(xᵢ)] to see how each value deviates from the mean. A larger variance means more risk or variability in your results. Statistics How To: AP Formulas
- Binomial Probability - Use this when you have a fixed number of trials and each is a success/fail. The formula P(X = x) = nCx × pˣ × (1−p)❿❻ˣ gives the chance of exactly x successes. It's perfect for things like coin flips or quality‑control checks. Statistics How To: AP Formulas
- Permutations & Combinations - Permutations (nPr) count ordered arrangements: nPr = n!/(n−r)!. Combinations (nCr) count unordered selections: nCr = n!/[r!(n−r)!]. Pick permutations when order matters, combinations when it doesn't. Fiveable's Probability Rules
- Law of Total Probability - Break a complex event into simpler, exhaustive cases B…Bₙ. Then sum P(A|Bᵢ)×P(Bᵢ) across all i to get P(A). It's a handy way to combine different scenarios. Fiveable's Probability Rules