Engineering Board Exam Reviewer · Hypergeometric, Poisson, and Geometric Distributions · medium

A lot of 20 items contains 5 defective ones. Four items are sampled without replacement. What is the probability that exactly 1 is defective?

  1. 0.4696
  2. 0.4219
  3. 0.2817
  4. 0.25

Answer

A. 0.4696

Solution

Hypergeometric: P= 5C1·15C320C4=5(455)/4845=0.4696.

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