Talk:Complementary event

Statistics High‑importance

	This article is within the scope of WikiProject Statistics, a collaborative effort to improve the coverage of statistics on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.StatisticsWikipedia:WikiProject StatisticsTemplate:WikiProject StatisticsStatistics
High	This article has been rated as High-importance on the importance scale.

Mathematics Mid‑priority

	Mathematics portal This article is within the scope of WikiProject Mathematics, a collaborative effort to improve the coverage of mathematics on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.MathematicsWikipedia:WikiProject MathematicsTemplate:WikiProject Mathematicsmathematics
Mid	This article has been rated as Mid-priority on the project's priority scale.

Mathematical error

Latest comment: 20 years ago1 comment1 person in discussion

Someone seems to be under the impression that if Pr(A) + Pr(B) = 1 then A and B are complementary. That is not true. For example, suppose one randomly chooses a number from the set { 1, 2, 3, 4}, the four numbers being equally probable. The probability that one gets 1 is 1/4, and the probability that one gets either 1, 2, or 3 is 3/4 so the sum of the two probabilities is 1. But obviously these events are not complementary; the complement of {1} is {2, 3, 4}, not {1, 2, 3}. Michael Hardy 01:19, 6 October 2005 (UTC)Reply

This page was redesigned at the edge.

A page that knows where it met you.

Talk:Complementary event

Mathematical error