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Module 2 · Probability Foundations · Topic 7

Independence

Independent Events. Two events are independent if the occurrence of one does not change the probability of the other. Formally, A and B are independent if P(A | B) = P(A).

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In the full lesson

  • Testing Independence (formula)
  • Worked Example (example)
  • Independence vs Mutually Exclusive (tip)

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Key formulas

From the Probability Foundations formula sheet

  • Conditional Probability: P(A | B) = P(A and B) / P(B) - Probability of A after restricting attention to cases where B occurred.
  • Bayes' Theorem: P(A | B) = P(B | A)P(A) / P(B) - Updates a prior probability after observing evidence.

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Related glossary terms

  • Independence: Two events are independent when one occurring does not change the probability of the other. Example: Two separate fair coin flips are independent.

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