{ localUrl: '../page/expected_value.html', arbitalUrl: 'https://arbital.com/p/expected_value', rawJsonUrl: '../raw/4b5.json', likeableId: '3609', likeableType: 'page', myLikeValue: '0', likeCount: '1', dislikeCount: '0', likeScore: '1', individualLikes: [ 'EricBruylant' ], pageId: 'expected_value', edit: '4', editSummary: 'moved to expected value, edited clickbait', prevEdit: '3', currentEdit: '4', wasPublished: 'true', type: 'wiki', title: 'Expected value', clickbait: 'Trying to assign value to an uncertain state? The weighted average of outcomes is probably the tool you need.', textLength: '1347', alias: 'expected_value', externalUrl: '', sortChildrenBy: 'likes', hasVote: 'false', voteType: '', votesAnonymous: 'false', editCreatorId: 'EricBruylant', editCreatedAt: '2016-10-13 16:20:55', pageCreatorId: 'MichaelCohen', pageCreatedAt: '2016-06-14 20:25:25', seeDomainId: '0', editDomainId: 'AlexeiAndreev', submitToDomainId: '0', isAutosave: 'false', isSnapshot: 'false', isLiveEdit: 'true', isMinorEdit: 'false', indirectTeacher: 'false', todoCount: '0', isEditorComment: 'false', isApprovedComment: 'true', isResolved: 'false', snapshotText: '', anchorContext: '', anchorText: '', anchorOffset: '0', mergedInto: '', isDeleted: 'false', viewCount: '73', text: 'The expected value of an action is the [-mean] numerical outcome of the possible results weighted by their [-1rf]. It may actually be impossible to get the expected value, for example, if a coin toss decides between you getting \\$0 and \\$10, then we say you get "\\$5 in expectation" even though there is no way for you to get \\$5.\n\nThe expectation of V (often shortened to "the expected V") is how much V you expect to get on average. For example, the expectation of a payoff, or an expected payoff, is how much money you will get on average; the expectation of the duration of a speech, or an expected duration, is how long the speech will last "on average."\n\nSuppose V has discrete possible values, say $V = x_{1},$ or $V = x_{2}, ..., $ or $V = x_{k}$. Let $P(x_{i})$ refer to the probability that $V = x_{i}$. Then the expectation of V is given by:\n\n$$\\sum_{i=1}^{k}x_{i}P(x_{i})$$\n\nSuppose V has continuous possible values, x. For instance, let $x \\in \\mathbb{R}$. Let $P(x)$ be the continuous probability distribution, or $\\lim_{dx \\to 0}$ of the probability that $x<V<(x+dx)$ divided by $dx$. Then the expectation of V is given by:\n\n$$\\int_{-∞}^{∞}xP(x)dx$$\n\n## Importance ##\n\nA common principle of reasoning under uncertainty is that if you are trying to achieve a good G, you should choose the act that maximizes the expectation of G.', metaText: '', isTextLoaded: 'true', isSubscribedToDiscussion: 'false', isSubscribedToUser: 'false', isSubscribedAsMaintainer: 'false', discussionSubscriberCount: '2', maintainerCount: '2', userSubscriberCount: '0', lastVisit: '', hasDraft: 'false', votes: [], voteSummary: 'null', muVoteSummary: '0', voteScaling: '0', currentUserVote: '-2', voteCount: '0', lockedVoteType: '', maxEditEver: '0', redLinkCount: '0', lockedBy: '', lockedUntil: '', nextPageId: '', prevPageId: '', usedAsMastery: 'false', proposalEditNum: '0', permissions: { edit: { has: 'false', reason: 'You don't have domain permission to edit this page' }, proposeEdit: { has: 'true', reason: '' }, delete: { has: 'false', reason: 'You don't have domain permission to delete this 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