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Distributions and testing
Lesson 1 of 10

The binomial distribution

Objective. Model repeated independent trials with X ~ B(n, p).

The key idea

Binomial applies when there is a fixed number of independent trials, each with two outcomes and constant probability.

Worked example

X ~ B(10, 0.3). Find P(X = 2).

Find P(X = 2)
Illustrated card showing Find P(X = 2)
  1. 1P(X = 2) = C(10,2) × 0.3² × 0.7⁸.
  2. 245 × 0.09 × 0.05765.

Answer: ≈ 0.233

Practice

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