Math · Algebra 2 ★★☆ Medium UNIT 10 OF 0

Probability and Statistics — Free Algebra 2 Review Games.

This unit covers permutations and combinations, binomial probability and normal distribution — essential concepts for Algebra 2. Use our interactive study games to test your understanding, or review questions in traditional format below.

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Quick summary

This unit covers permutations and combinations, binomial probability and normal distribution — essential concepts for Algebra 2. Use our interactive study games to test your understanding, or review questions in traditional format below.

What you need to know

Key Concepts Breakdown

1 Permutations and Combinations

Permutations count arrangements where order matters; combinations count selections where order does not matter. Students must know when to apply each formula and how to handle factorial expressions. The formulas are nPr = n! / (n-r)! and nCr = n! / (r!(n-r)!).

Key Points

  • Use permutations when order matters (e.g., rankings, passwords, seating arrangements)
  • Use combinations when order does not matter (e.g., choosing a committee, selecting items)
  • n! means the product of all positive integers from 1 to n; 0! = 1
  • nCr is also written as C(n,r) or the binomial coefficient notation
Example

A class of 10 students needs to elect a president, vice president, and secretary. How many different outcomes are possible?

Explanation

Order matters here because each position is different, so use permutations: 10P3 = 10! / (10-3)! = 10! / 7! = 10 × 9 × 8 = 720. If instead you were just choosing 3 students for a committee (no specific roles), you would use 10C3 = 10! / (3! × 7!) = 120.

2 Binomial Probability

Binomial probability applies when there are exactly two outcomes (success/failure), a fixed number of trials, and each trial is independent with the same probability of success. The formula is P(X = k) = C(n,k) × p^k × (1-p)^(n-k). Students must correctly identify n, k, and p from a word problem.

Key Points

  • n = total number of trials, k = number of successes, p = probability of success on one trial
  • The combination C(n,k) counts how many ways k successes can be arranged among n trials
  • P(at least one) = 1 - P(none) is a common shortcut on exams
  • Mean of a binomial distribution: μ = np; standard deviation: σ = √(np(1-p))
Example

A multiple-choice quiz has 5 questions, each with 4 answer choices. If a student guesses randomly on every question, what is the probability of getting exactly 3 correct?

Explanation

Here n = 5, k = 3, and p = 1/4 = 0.25. Plug into the formula: P(X = 3) = C(5,3) × (0.25)^3 × (0.75)^2. C(5,3) = 10, (0.25)^3 = 0.015625, and (0.75)^2 = 0.5625, giving 10 × 0.015625 × 0.5625 ≈ 0.0879, or about 8.8%.

3 Normal Distribution

The normal distribution is a symmetric, bell-shaped curve defined by its mean (μ) and standard deviation (σ). Students must be able to use the Empirical Rule (68-95-99.7) and calculate or interpret z-scores to find probabilities and percentiles. On exams, problems typically require converting raw scores to z-scores and using a z-table or calculator.

Key Points

  • Empirical Rule: 68% of data falls within 1σ, 95% within 2σ, 99.7% within 3σ of the mean
  • Z-score formula: z = (x - μ) / σ; a z-score measures how many standard deviations a value is from the mean
  • A positive z-score is above the mean; a negative z-score is below the mean
  • To find the percent of data above a value, compute the z-score then subtract the table area from 1
Example

The scores on a history test are normally distributed with a mean of 74 and a standard deviation of 8. What percentage of students scored between 66 and 90?

Explanation

Convert each score to a z-score: z = (66 - 74) / 8 = -1 and z = (90 - 74) / 8 = 2. Using the Empirical Rule, 68% of data falls within 1 standard deviation (between 66 and 82), and 95% falls within 2 standard deviations (between 58 and 90). The area from z = -1 to z = 2 is approximately 68%/2 + 95%/2 = 34% + 47.5% = 81.5% of students.

FAQ

Questions, answered.

What is Probability and Statistics?

Probability and Statistics is Unit 10 of Algebra 2, covering permutations and combinations, binomial probability and normal distribution.

How to study for Algebra 2 Unit 10?

Start with the Quick Summary above, review the Key Concepts, then test yourself with our interactive study games. Aim for 80%+ accuracy before moving on.

How many questions are in this unit?

This unit has 27+ review questions across 5 different game modes.