Solving problem N3923 Bayesian probability theory

Solving problem N3923 Bayesian probability theory

3923. Two factories produce the same products, the first one giving 80%, and the second 20%. Marriage of the first plant is 3%, the second - 12%. The sample taken at random turned out to be defective. What is the probability that it is made at the second plant?

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Detailed solution. Decorated in Microsoft Word 2003 (Quest decided to use the formula editor)